11. Terry Winograd [1]
[Historical note: This discussion was planned to appear in the 1992 book version of Linguistic Theory, but at the time it. was removed party because the publisher objected (as they always do) to the length of the book, and partly because Winograd himself took angry exception to some of my “snide’ comments. Special points of contention were his sudden switch of allegiance from his once-famous Hallidayan functionalism to a formalism that would sustain his fat, separate volume in Syntax and to Martin Heidegger, whose writings are barely comprehensible even to me in the original German, and seem merely pompous and absurd in English, and who (unbeknownst to Winograd).never in his whole life publicly abjured his fervent commitment to National Socialism in Hitler’s Germany. This has been irrefutably demonstrated by Hugo Ott’s 1988 biography Martin Heidegger: Unterwegs zu seiner Biographie, which adduces documentation long suppressed. I release the chapter now that Winograd has moved on to very different things, such as turning Searle’s tepid ‘speech acts’ theory into a profitable office-software (10.93f).]
[1. The key for Winograd citations is: LAP: ‘A language action perspective on the design of cooperative work’ (1987-88); LC: Language as a Cognitive Process (1983); MSF: Moving the semantic fulcrum’ (1985); UC: Understanding Computers and Cognition (1986) with Fernando Flores (cf. Note 22); and UN: Understanding Natural Language (1972). I also made one citation of his ‘Guest Editor's Introduction’ (1988).
10.1 Terry Winograd's work
is an obvious choice for demonstrating how ‘artificial intelligence’, or
‘AI’ as it is usually called, makes use of ‘research on linguistic
theory’ (LAP 6). He was a pupil of Halliday's, and the breadth of his concerns
is attested by the titles of his books: Understanding
Natural Language (1972, hereafter UN), Language
as a Cognitive Process (1983, hereafter LC), and Understanding Computers and Cognition (1986, hereafter UC). In his
works linguistics is central, whereas it is disregarded in many AI works on
‘natural language’ (e.g. Raphael 1968), and vigorously opposed in some (e.g.
Schank, Goldman, Rieger & Riesbeck 1975).
10.2 Winograd's 1972
dissertation, an implementation of Halliday's ‘systemic grammar’ in a
computer program, was an undisputed landmark. It was deemed ‘sufficiently
general and important’ to be printed in full as ‘an entire issue’ of a
prestigious journal, Cognitive Psychology
(UN vii), and soon after as a book. Instead of merely parsing sentences into
trees like the pokey ‘Mitre’ program (Zwicky et al. 1965), Winograd's
program both embodied a linguistic model and ‘simulated’ a conversational
partner, a ‘robot’ that engaged in ‘English dialogue’ with a human (UN
1, x) (10.11f). This banner achievement fuelled hopes that AI would not only
enable computers to use natural language instead of programming languages, but
would reveal basic properties of language and mind by means of simulation and
real-time interaction.
10.3 Winograd's next book
project was to be a mammoth survey of ‘models of language’, both in
‘linguistics’ and ‘computer science’ (LC viif), thus integrating natural
and formal languages into one perspective. After ‘nearly ten years’, during
which the writing ‘underwent fission into volumes’ (LC vii, xi) a 640-page
tome on ‘Syntax’ appeared, wherein he backed away from ‘systemic
grammar’ toward more ‘generative’ approaches. A projected companion,
volume on meaning’, however, did not appear, and Winograd now tells me (by
letter) that he has come to consider it ‘an impossible project’, and his
‘thinking has gone in a different direction’ (cf. 10.53). Just how different
can be seen from his latest book, co-authored with Fernando Flores, which
emphatically questions the ability of AI to model the understanding of natural
language. A strange career on the face of it, but a close reading of
Winograd's works reveals some strategic continuity and canny policy behind the
shifts and manoeuvres.
10.4 Winograd's
dissertation illustrated ‘a newly developing paradigm’ ‘grown up from
working with computers’ (UN ix) (cf. 10.40). For inquiring ‘what kind of
process could be going on to produce’ ‘the highly complex and organized
behaviour’ of ‘language’, ‘computers and computer language give us a
formal metaphor’ to ‘model the processes and test the implications of our
theories’. Although ‘our models’ remain, incomplete’ and, their
‘connection’ ‘with the processes going on in the human mind’ ‘is not
yet clear’, they do offer ‘a clear framework for thinking about’ how
people ‘understand and respond to natural language’. Major ‘reasons for
writing such programs’ included: ‘increasing the ability of computers to
communicate with people’, ‘clarifying what language is and how it works in
human communication’; and ‘discovering the basic principles underlying,
intelligence’ (UN ixf). ‘A usable language-understanding system’
encourages us to ‘make all of our knowledge’ about ‘the entire language
process’ ‘explicit’ and thus affords ‘a rigorous test for linguistic
theories’ and a means for ‘making new theories’ (UN 2) (cf.10.14, 46, 73).
And since ‘language is one of the most complex and unique of human activities,
understanding its structure may lead to a better understanding of how our minds
work’, above all in ‘areas which involve integrating large amounts of
knowledge into a flexible system’ (cf. 10.42, 54, 56, 72; 11.4, 21). Such
prospects signal a sly ambivalence in the title of the book: we might better
‘understand natural language’ (as a human capacity) by seeing how a computer
goes about ‘understanding’ samples of it (as English dialogue).
10.5 Accordingly, Winograd
set the scope of the project very wide. If ‘a person’ ‘makes full use of
his knowledge and intelligence to understand’ ‘a sentence’, then an
adequate model demands that we ‘deal in an integrated way with all aspects of
language': ‘syntax, semantics, inference’, ‘knowledge, and reasoning’
(UN x, 1). A model of ‘intelligence needs a highly structured and coordinated
body of knowledge rather than a set of separate uniform facts or axioms’ (UN
142) (cf. 10.26, 39, 48, 71; 11.21). ‘Adding new information’ requires
‘understanding its relationship’ to ‘whatever is already there': ‘a
problem-solving activity rather than a clerical one’ (cf. 10.10, 30, 73.
11.12f, 25, 51). A computerized ‘language understander needs to have an
interpreter’ for ‘deciding how to use’ ‘each new sentence’,
‘checking for consistency’, ‘creating new data or types of data in
storage, modifying theorems’, and so on.
10.6
At that stage of his work, Winograd took pains to refute the commonplace charge
that models of entities which ‘exist in the speaker's and hearer's minds’
are ‘mysterious’ and ‘meaningless’ (UN 26) (cf. 4.8f. 5.10; 7.9ff; 8.24;
10.39; 12.38). He stressed the capacity of the ‘structure of concepts which is
postulated’ to be ‘manipulated’, ‘obeyed, answered, and added to’
‘within the computer’. He drew a ‘comparison to the use of “forces” in
physics’ (cf. 7.16, 32; 6.62; 12.49, 59. 13.11).
‘We have no way of directly observing a force like gravity, but by
postulating Its existence, we can write equations describing it and relate’
them to ‘events’ ‘Similarly, the “concept” representation of meaning
is not intended as a direct picture of something which exists in a person's
mind’, but ‘a fiction that gives us a way to make sense of data and to
predict actual behaviour’, and thus to ‘gain a better understanding of
language use’. For example, we can ‘justify using concepts’ if the
‘system’ is ‘thereby enabled to engage in dialogs that simulate in many
ways the behaviour of a human language user’ (cf. 11.88; 13.33).
10.7
Within ‘the field’ of ‘language understanding systems’, Winograd
distinguished four basic types’ (UN 34). First, ‘special
format’ systems were ‘designed’ for 5 ‘particular subject matter’,
and treated as ‘relevant’ only the ‘information In a sentence’ that fit
the ‘format’ (UN 34f). Naturally, they lacked ‘flexibility’ and were
‘minimally concerned with the complexities of language’, but their,
restricted domain’ and ‘special-purpose heuristics’ could produce
‘impressive results’. Second, ‘text-based systems’ had ‘a body of text stored directly under’
an ‘indexing scheme’; ‘an English, sentence input’ was ‘interpreted as
a request to retrieve a relevant sentence or group of sentences from the
text’. Third, ‘limited logic systems
used a ‘more formal notation’ in place of ‘English sentences in the base
of stored knowledge’, thereby ‘freeing simple information’ from one
‘specific way of expressing it in English’ (UN 36). Then the ‘bulk of
effort’ got invested in ‘translating’ between the ‘English input’ and
the ‘assertion format’ (cf. 13.51). The ‘limited logic’ consisted in
‘some mechanisms for accepting more complex information and using it to deduce
the answers to more complex questions’ by means of ‘inference’ (UN 36f).
10.8
Fourth, ‘General deductive systems’ had
their ‘knowledge’ ‘expressed in some standard mathematical notation (such
as first order predicate calculus)’, so that, the work logicians have done on
theorem proving could be utilized’ (e.g. Robinson 1965) (UN 38) (cf. 10.78).
‘The procedure is uniform’ rather than ‘suited to a particular subject’;
and ‘if any proof is possible’, ‘the procedure will eventually find it’,
but ‘may take a very long time’. This method provided ‘a way to present
complex information as data rather than embedding it into the inner workings of
the language-understanding system’ (UN 38f). The user’ could ‘describe a
body of knowledge’ ‘in a “neutral” way’, and the ‘system was
applicable to any subject’. But such systems had ‘a low level of
practicality’ and ‘tremendous problems of efficiency’. ‘Predicate
calculus’ has ‘a serious deficiency’; since first-order logic is a
declarative rather than’ a procedural ‘language, specifying how to do
something’ is difficult’ without addling ‘strategy information’ (cf.
11.14ff. 13.17). ‘An important part of a person's knowledge concerns, how to
go about figuring things out’, deploying ‘large sets of heuristics and
procedures for solving problems at different levels of generality’ (cf. 9.14,
17, 10.5, 10, 15, 23, 29). Without this guidance, any ‘large set of axioms,
even well below the number needed for really understanding language’, gets it
‘bogged down in searching for a proof’. Indeed, in ‘a truly uniform
system, the theorem prover is forced to “rediscover and world” every time it
answers a question’, and ‘every goal forces it to start from scratch,
looking at all the theorems in the data base’ (UN 41). Thus, an emphasis on
‘abstract logical properties’ like ‘consistency and completeness’ ‘may
in fact be bad’ if the system tries to ‘prove’ something which is
‘false’, it will never ‘give up’ until it ‘exhausts every possible
way’.
10.9
Surmounting the drawbacks of these four types of system called for a more
judicious balance between ‘procedural
representations, which embody knowledge in the program, and declarative
representations, which emphasize the structure of the stored knowledge’
(LC 18) (cf. Winograd 1975). ‘New programming techniques’ were ‘needed’
for ‘using procedural information’ but ‘expressing it in ways which did
not depend on the peculiarities and special structure of a particular program or
subject of discussion’ (UN 40). So ‘procedural
deductive systems’ were developed whose ‘language was goal-oriented’
and not ‘concerned about the details of interaction among procedures’.
The ‘advantages’ were ‘a flexible control structure’ and ‘a
uniform notation’ that allowed ‘adding new theorems without relating them to
others’ (UN 41; cf. LC 380; 10.48). These systems could ‘handle simple
assertions’ as well as ‘complex information’ ‘expressed as
procedures’, including knowledge of how best to go about attempting a
proof’, e.g., by ‘trying theorems in a particular order’, or taking them
from a ‘specified set’, or ‘setting up a subgoal’ with ‘arbitrarily
complex calculations’ (UN 40f). The ‘PLANNER language’ used in Winograd's
own model for various tasks, such as ‘representing knowledge’,
‘manipulating meanings’, ‘making deductions’, and so on (UN 4, 6f, 40f,
108-17, 126-38, 152), was a system of this type (cf. Hewitt 1973).
10.10 To
attain the desired breadth, Winograd's system had an assembly of components.
These included ‘a parser, a recognition grammar of English, programs
for semantic analysis, and a general problem-solving system’ (UN 1).
‘Heuristic programs’ were supplied for ‘using syntactic, semantic,
contextual, and physical knowledge’, and for ‘reasoning about the subject’
being ‘discussed’ (UN 1, x) (cf. 10.5). The system also had ‘a detailed
model of a particular domain’ (a ‘world’) and even a ‘model of its own
mentality’, so that it could ‘remember and discuss plans and actions as well
as carry them out’ (UN 1, 4; cf. 10.12, 16, 22ff, 25, 28, 44, 69). Thus,
‘the system had some understanding of its own motives’ and could ‘remember
what it did, not how the request was worded’ (UN 13).
10.11
The system created ‘a simulated robot with an arm and eye’ (UN x, 2, 117f).
The ‘robot’, whose name was ‘SHRDLU’,[2], could ‘manipulate
objects’, namely ‘blocks’ of various sizes and shapes, ‘on a table': a
limited task, but still requiring substantive knowledge about ‘size, shape,
colour, and location’ in ‘three dimensions’, and about ‘spatial
relations between objects’, such as ‘support’ (UN x, 2, 118f). ‘The
events In the world are actions taken by the robot’ ‘displayed’ ‘on a
video screen’ ‘in real time so that the human can get visual feedback’;
but they could ‘theoretically be sent directly to a physical robot system’
(UN 121, 6f, LC 391, UC 109). ‘The robot grasps by moving its hand directly
over the centre of an object’ and ‘turning on a magnet’ the ‘object’
is then ‘moved along with the hand’ and ‘ungrasped’ when ‘there is
something supporting’ it (UN 121).
10.12
The robot's chief talent was to carry on ‘an interactive English dialogue’
with a person, ‘accepting information’, ‘answering questions’, and
‘executing commands’ in the world of ‘blocks’ (UN 1, x). ‘Where
running compiled, the system was fast enough to carry on a real time
discourse’; ‘each sentence took from 5 to 20 seconds to analyse and, respond
to, and the display’ could ‘move at the speed of a real arm’ (UN 7f).
SHRDLU's ‘knowledge about the properties of particular physical world’ and
its ways of ‘achieving goals in this world’ were ‘designed less as a
realistic simulation of a robot than to give the system a world to talk about’
(UN 6). SHRDLU's ‘memory of motion events’ was used ‘to reconstruct the
scene’, and ‘the data base’ was made ‘current’ ‘whenever an object
was moved’, here again for purposes of discourse (UN 125, 119f).
10.13
Just as for Halliday ‘the grammar is the central processing unit of a
language’, ‘the main coordinator of the language understanding process’ in
Winograd's system was ‘the Grammar’
(IF xxxiv, UN 5) (cf. 9.23, 32, 37). ‘The grammar’ ‘was based on’ and
‘adapted’ from early versions (1967-68, 1970) of Halliday's ‘theory of
systemic grammar’, ‘which emphasizes the limited and highly structured sets
of choices made in producing a syntactic structure and abstracting the features
that are important for conveying meaning’ (UN 3, 16f, 47 62) (cf. 10.13, 22,
66f; 9.3, 19, 21, 81). ‘A system’
is ‘a set of mutually exclusive features’ ‘among which we will choose
one’ when ‘its entry condition’ is ‘satisfied’ -- in ‘the simplest case
(and most common)’, the presence of a single other feature’ (UN 19)
(9.19).'These choices are represented by ‘syntactic features attached to all
levels’ according to ‘a set of system networks explicitly describing their
logical independence’ and ‘interaction’, instead of ‘a “deep
structure” tree’ (UN 3, 16) (cf. 10.19f, 23, 26, 32).[3] This ‘systemic
analyses’ enables ‘a coherent outline of the way English is structured,
rather than concentrating on describing particular linguistic phenomena in
detail’ or striving to be ‘definitive’ (UN 3f). ‘The exact way the
choices are “realized” in the final form is a necessary but secondary part
of the theory’ (UN 16).
10.14
‘The Grammar’ was ‘written to handle’ the ‘three basic ranks of units, the clause, the group, and the word’ (UN 5, 17)
(cf. 9.33ff- 13.29). ‘In this analysis, the, word is the basic building block’ and ‘is not chopped into
hypothetical bits’, but is rather viewed as ‘exhibiting features’ (like
“infinitive”’) (cf. 13.30). A further operational ‘distinction’ is
made, though not a ‘sharp’ one’, between ‘function words’, those,
defined’, in terms of their function in sentence structure’, and ‘content
words’, those which do not ‘presume detailed knowledge of the syntax of the
language’ (UN 30). ‘The definition of each word’ is a ‘complex program
describing its different uses’ and designed ‘to be run at the appropriate
time in the semantic analysis’. Having ‘the procedures actually run in an
integrated language understanding system’ offers ‘a strict test for the
representation of the meaning of a word’ (UN 30f).
10.15
‘Standard functions’ are used for ‘simple cases’, and ‘special
operations’ for ‘complex cases’, e.g. ‘a heuristic program for
understanding back-references’ (UN 30) (cf. 10.23, 78). Thus, ‘by making the
formalism for specifying grammars a programming language, we enable the grammar
to use special tools to handle complex constructions and irregular forms’ (UN
22) (cf. 13.40). ‘We can set up programs to define’ ‘idioms’ or ‘words
like "and" and "or"‘; with these, ‘processing can be
interrupted at any point and other computations (either semantic or syntactic)
can be performed before going on’ (UN 21) (cf. 10.22f).
10.16
The ‘groups’ were divided’ into
‘noun group, verb group, preposition group, and adjective group’ (UN 17)
(cf. 9.57, 75-81). ‘Each group’ ‘has a particular function in conveying
meaning: noun groups describe objects; verb groups carry complex messages about
the time and modal (logical) status of an event or relationship; preposition
groups describe simple relationships; and adjective groups convey other kinds of
relationships and descriptions’ (UN 18, 29). In this respect, ‘English
syntax’ is ‘good at conveying’ ‘basic elements’ of a ‘person's
"model of the world"’ (UN 28) (cf. 13.24). ‘Each group’ also has
‘slots for the words’, e.g., for ‘determiner’, ‘number, adjective,
classifier, and noun’ in ‘a noun group’ (9.77f).
10.17
‘Finally, the top rank’ and ‘primary unit of discourse’ is the clause’, which ‘is the most complex and diverse unit of the
language’ (UN 18, 47) (9.44). It can appear as, "Question",
"Declarative", or "Imperative", as "passive" or
"active", and can be used to express relationships and events
involving time, place, manner, and many other aspects of meaning’ as well as
the ‘focus of attention and emotion’. Also, ‘its structure indicates’,
what the speaker wants to emphasize’ or, question’, and signals ‘the
purpose of a utterance’ (UN 47, 49). ‘The sentence’,
in contrast, ‘is more a unit of discourse and semantics than a separate
syntactic structure’ or ‘unit’, and can be dealt with in terms of its
‘conjoining’ ‘clauses’ (UN 18, 47; cf. 9.82; 13.54). Due to, the
‘phenomenon called rankshift’ -- ‘one of the basic principles of systemic
grammar’ -- a ‘sentence’ may not have ‘a simple three layer structure’
in which ‘clauses are made up of groups, which are in turn made up of
words’, but one in which ‘a group’ ‘contains other groups’, or a
‘clause’ forms ‘part of other clauses’ or of ‘groups’ (UN 18, 50,
52) (cf. 13.54).[4]
10.18
‘Each unit has associated with it a set’ of ‘features,
which are of primary significance in conveying meaning’ and are ‘related by
a definite logical structure’ (UN 19) (cf. 10.14f, 23, 26, 32). For example,
‘word classes can be divided into
subclasses by the features assigned to individual words’, according to
‘arbitrary decisions as to whether a distinction between groups of words
should be represented by different classes or different features of the same
class’ (UN 66) (cf. 13.27). ‘In our dictionary, we simply list all syntactic
features the word has for all of the classes to which It can belong’, ‘the
verb having the most complex network of features of any word’ (UN 66, 70).
‘Each group can also exhibit
features just as a word can’, e.g. ‘"singular"‘ or
"definite''‘ for a ‘noun group’, or "negative''‘ for a ‘verb
group’ (UN 18).[5]
10.19
The ‘functions a syntactic
"unit" can have’, such as ‘Subject and Object’ in ‘a
transitive clause’, can be approached by considering ‘which features of a
syntactic structure are important to conveying meaning and which are just a
by-product of the symbol manipulations needed to produce the right word order’
(UN 20f). ‘In most current theories, these features and functions are implicit
in the syntactic rules’ (or "'deep structures"‘), and ‘there is
no attempt to distinguish significant features from the many other features we
could note about a sentence and which are also implied by the rules’ (cf.
10.67). ‘Systemic grammar’, however, uses ‘realization rules’ to
‘relate the set of features to the actual surface structure’, thereby
handling what ‘would be done by transformations in transformational grammar’
(cf. 9.10, 9[3], 9[20]; 10.64). For ‘recognition rather than generation’,
‘interpretation rules’ act as ‘the Inverse of realization rules’,
‘looking at a pattern, identifying Its structure, and recognizing its relevant
features’ (UN 21f) (cf. 13.57).
10.20
Obviously, Winograd was not following the ‘recent linguistic theories’ that
‘consider syntax as a proper study devoid of semantics’ (UN 16) (cf. 4.15;
5.61f 7.56; but see 10.52ff). There, ‘language is viewed as a way of
organizing strings of abstract symbols, and competence is explained’ with
‘symbol-manipulating rules’ (10.40, 43, 77). Such a method may ‘describe
in great detail’ how ‘sentences are put together’, but can provide only
‘the most rudimentary and unsatisfactory accounts of semantics’. Winograd's
SHRDLU system’, in contrast, thematically favours ‘the interaction between
syntax and semantics’ (UN 68f; cf. UN 3, 5f, 21f 29, 31f, 44, 47, 69, 73, 76,
89, 93, 101f, 127, 131f). The flexibility of writing a grammar as a program’
makes it easier both to handle the comp1exties of English syntax and to combine
the semantic analysis of language with the syntactic analysis in an intimate
way’ (UN 89). The ‘ability to integrate semantics with syntax is
particularly important in handling discourse, where the interpretation of a
sentence’ ‘may depend in complex ways on the preceding discourse and
knowledge of subject matter’ (UN 22) (cf. 5.57- 9.16- 11.86, 91).
10.21
Therefore, ‘the language process is not segmented into the operation of a
parser followed by the operation of a semantic interpreter; rather, the process
is unified, with the results of semantic interpretation being used to guide the
parsing’ (UN 22f) (cf. 7.49; 11.3, 34, 77). This tactic was justified not
merely on theoretical, but on operational grounds, as a matter of efficiency.
Without ‘semantic’ guidance, a purely syntactic parser expends time and
resources on possible structurings allowed by grammar but easily recognized as
yielding ‘contradictory’ or ‘meaningless interpretations’ (UN 127, 131).
The ‘dire danger of combinatorial explosion’ [6] can thus be met by ‘doing
the interpretation continuously’ ‘for each phrase’ and ‘immediately
looking into our memory to see which interpretation is meaningful In the current
context of discourse’ (UN 32) (cf. 10.65. 11.79).
10.22
‘Since the parser users systemic grammar, the semantic programs can look
directly for syntactic features such as ‘'Passive"‘ ‘to make
decisions about the meaning’ (UN 29). These programs being able to ‘work
separately, there is no need to wait for a complete parsing before beginning
semantic analysis’. Besides, ‘any semantic program has full power to use the
deductive system’, and can ‘call the grammar to do a special bit of parsing
before going on’. ‘The semantic analysis’ is thus both
"bottom-up"‘, in that ‘each structure is analysed as it is parsed;
and ‘"top-down"‘ in that the ‘specialist programs’ allow it to
anticipate what ‘larger structure’ is to be ‘analysed’ (UN 29f, 22) (cf.
10.59, 62 10 [11], 10[15]; 11.13, 19, 25, 32, 55, 59, 73, 77f, 95, 97- 13.32).
10.23
Furthermore, we can ‘use the overall context in determining the plausibility
of a particular interpretation’ (UN 32). Winograd proposes that ‘semantic
theory can account for three different types of context’. ‘Local
discourse context’ ‘covers the discourse immediately preceding and Is
important to semantic mechanisms like pronoun reference’ (e.g. for "'How
many of them were there then?''‘). Overall
discourse context’ covers ‘general subject matter’ (e.g. for "The
group didn't have an identity''‘ in ‘discussing mathematics or
sociology’). Finally ‘knowledge about
the world’ ‘affects our understanding of language’ (e.g. for "The
city councilmen refused the demonstrators a permit because they ‘''advocated revolution"‘) (UN 33) (cf. 11.20). In
Winograd's system, most of this discourse knowledge is called on by semantic
specialists and by particular words such as "one", "it",
"then", "there", etc. (UN 33) (cf. 10.29, 31). These ‘specialists
are programs’ designed to ‘work separately’, to be ‘expert In looking at
particular’ data’, and to ‘create parts of a complete description of the
meaning of a sentence by building complex list structures’ (UN 33, 29, 126).
10.24 So
broad a view of semantic theory reveals ‘the importance of a comprehensive
representation of meaning’ (UN 3). Winograd envisions ‘three different
levels’ at which ‘semantic theory must describe relationships’ (UN 28).
The ‘first’ level should ‘define the meaning of words’, in the
‘limited sense’ of a ‘formal description attached to a word which allows
it to integrated into the system’; the ‘formalisms’ should ‘allow users
to add to vocabulary in a simple and natural way’, and should ‘hand1e quirks
and idiosyncrasies of meaning, not just well-behaved standard words’ (UN 28)
(cf. 10.15; 13.40). The second
‘level’ should ‘relate meanings of groups of words in syntactic
structures’. The third level should ‘describe how the meaning of a sentence
depends on context': both on its ‘linguistic setting’ and on its
‘real-world setting’.
10.25
‘A system of semantic features’ [7]
is a further means to control the ‘semantic interpretations of any phrase or
sentence’ (UN 3, 6, 32, 76, 127, 131) (cf. 10.14f, 23, 32; 13.30). ‘A
network’ of ‘features’ can be ‘kept on property lists and used for an
initial phase of semantic analysis’ (UN 6). ‘The features subdivide the
world of objects and actions into simple categories’ and ‘rough classes such
as "animate", " inanimate", " physical",
"abstract", etc. (UN 6, 31) (cf. 7.69; 10.18f, 22, 31). This approach
is claimed to be a ‘complete representation of meaning’ or a full-blown,
semantic theory’, as Katz and Fodor (1964) imagined (UN 31f) (cf. 5.76. 7.67,
77). ‘There is no self-contained set of "primitives" from which
everything else can be defined’ (cf. 11.24; 13.59). Yet for ‘useful
purposes’ within a ‘model of the world’, we can ‘consider some concepts
as ‘"atomic"‘, with a ‘meaning’ that is not a ‘combination
of other more basic concepts’ (UN 26f). What counts as ‘atomic’ is decided
not by some ‘logical status’ or ‘sharp dividing line’, but by
‘distinctions’ that fit ‘the needs of the particular language
communication’ and by the consensus underlying the ‘close similarity between
the models held by speaker and listener’.
10.26
Although ‘there has never been a clear definition of what the field of
"semantics" should cover’, attempting to program computers to
understand natural language has clarified what a semantic theory has to do’
(UN 28). ‘A notation for representing certain kinds of meaning’ can be
devised with ‘a pragmatic approach’ rather than ‘a deep philosophical’
one (UN 25f) (cf. 11.3, 22, 40; 13.51). ‘Language ‘is inextricably enmeshed
in the knowledge’ ‘people have about the world': ‘not a neat collection of
definitions and axioms, complete, concise, and consistent’. ‘Rather, it is a
collection of concepts designed to manipulate ideas’, and is liable to be,
incomplete, highly redundant, and often inconsistent’ (UN 26f) (cf. 5.86;
9.110; 10.5, 8, 39, 71; 11.24). ‘Definitions are circular, with each concept
depending on the other concepts’. ‘The meaning of a concept’ might indeed
‘depend on entire knowledge of the speaker, not just the kind’ of knowledge
‘in a traditional dictionary’ (cf. 4.14. 5.28; 10.90; 11.20).
10.27
The ‘primary goals’ ‘of a semantic theory’ should not be "'the
number and content of the readings of a sentence"‘, or potential
"anomalies''‘ and ‘"paraphrase relations"‘ (UN 33) (cf.
7.61). All these are only ‘by-products of the analysis made possible by a more
complete semantic theory’ (UN 33f) and can be handled in an operational way.
An ‘anomaly’ occurs if ‘the system produces no possible
interpretations’; ‘two sentences are paraphrases if they produce the same
representation to the internal formalism’; and so on. Such instances too
‘depend on the entire range of in the internal formalism, ways in which
language communicates meaning’ in ‘the interaction of context with
understanding’, and not just ‘on a restricted subset such as the logical
relations of markers’ (cf. 7.63; 10.62). .
10.28 To
‘gain flexibility and power’, ‘knowledge can be represented in the form of
procedures written in special
languages’, ‘rather than tables of rules or lists of patterns’ (UN If)
(cf. 10.9). Then ‘each piece of knowledge’ ‘can call directly on any
other’ ‘in the system’ (cf. 10.22). And ‘each definition is a program’
able to ‘examine the description’ and ‘produce an appropriate meaning
relative to the object being described’ (UN 129, 143). So in Winograd's
system, ‘both the semantic knowledge and the definitions of individual words
were in the form of programs’ which ‘interpret’ ‘words’ in terms of
‘definitions’ in ‘the dictionary’ (UN 3, 6) (10.14).
10.29 In
addition, we can ‘allow each predicate’ ‘to have associated with it a
program which knows how to evaluate its "priority" in any given
environment’ (UC 130). We might select ‘a single number’ or ‘a complex
heuristic program which takes into account the current state of the world and
the discourse’. Also, we can ‘include mechanisms for carrying along with
each semantic structure an accumulated plausibility rating’. ‘As a semantic
structure is built, it takes on the sum of the plausibilities of its
components’ (UN 150). For a ‘pronoun’ like "'it"‘, say, ‘a
special heuristic program’ can ‘look into the discourse for all the
different things it might refer to and assign a plausibility value to each,
according to’ ‘its position in syntactic structure’, ‘the form of its
determiner’, and so on (UN 158, 160) (cf. 10.23, 31). Where appropriate, the
‘decision’ about ‘which is better’ can wait until ‘the end’ of
‘the sentence’, or, as a ‘last resort’, the system can ‘ask for
clarification’ (UN 158; cf. UN 150).
10.30 The ‘novelty’ of
Winograd's method was to ‘approach semantics’ ‘as a practical problem of
relating words and syntactic structures to a comprehensive logical formalism within
a specific problem-solving system’ (UN 5). The, semantics’ was built for a
‘detailed analysis of linguistic structures to extract an expression of their
meaning’ CUN 3). This design fits Winograd's view -- one he later repudiated
-- of ‘the process of understanding language as a conversion from a string of
sounds or letters to an Internal representation of meaning’ (UN 23) (cf.
10.79). ‘To do this’, the ‘system must have some formal way to express its
knowledge’ and to, represent the "meaning" of a sentence In this
formalism’, e.g. in terms of "objects'‘, " relations", and
"properties"‘ (UN 23f, 27).[8] ‘The formalism must be structured
so the system can use Its knowledge In conjunction with a problem-solving
system’ to ‘make deductions, accept new information, answer questions, and
interpret commands’ (UN 24). (10.4, 8, 12).
10.31
As we have seen, Winograd's system foregrounds the process of ‘understanding’, as the book's title promised. The ‘production’
of ‘discourse’ in contrast, received only limited treatment under, four
aspects’ (UN 163). The system made, patterned
responses’, either ‘fixed’ (like "0K''‘ or "'I
understand"‘) for specific situations’, or ‘more complex’ for
‘"filling in the blank" with a phrase’ ‘from the input’ (like
"'Sorry, I don’ t know the word ____"‘ or "'I'm not sure what
you mean by _____"‘) (UN 163f). The latter kind of response, which may
‘involve manipulating the determiners of the phrase’, is useful when ‘the
system cannot figure out what is referred to’ or tries to ‘handle
ambiguity’ (UN 163f). ‘Answering
questions’ was done according to the ‘types of response people
expect’, with ‘no attempt’ ‘at full sentences, since people rarely
answer questions’ that way (e.g., ‘"which block is in the box?" --
"the red one"‘). ‘Naming
objects and events’ was done by consulting the ‘features’ like
‘colour and size’ of ‘objects’ (e.g. ‘"a large green
cube"‘), or noting which ‘object’ was ‘involved’ in which
‘event’ (e.g. "'put a large red cube on the table"‘) (UN
166ff).[9] Finally, ‘fluent discourse’
was sought with the aid of ‘three’ ‘devices’ : ‘combining
identical descriptions’ to ‘avoid redundancy’ (e.g. to get "'three
small red cubes"‘); ‘using substitute nouns’ ( e.g. ‘"a large
one"‘); and ‘using "it" and "that"‘ when
‘referring to the same object more than once’ (UN 163, 168f) (cf. 10.23,
29). These various tactics help to prevent ‘awkward and stilted responses’
that might be ‘at times incomprehensible’ (UN 168). Some responses may seem
‘verbose’ in providing ‘extra information’, but this too ‘usually
gives a natural sounding answer’ and an ‘intelligent’ impression of
‘telling the questioner information he would be interested In knowing, even
when he doesn't ask for it explicitly’ (UN 140).
10.32 My
summary should give some idea of Winograd's ‘SHRDLU’ system. As is typical
of AI work, the main thrust was to get the system running on a computer well
enough so that It could carry out reasonably human-like dialogues without either
making ridiculous mistakes or breaking down, i.e., stopping, exploding, or going
into endless loops. A natural language system that runs successfully will seem
‘intelligent’, albeit by ‘artificial’ means, thanks to the ‘intimate
connection between ‘intelligence and language’ (UC 107) (cf. 10.43, 75,
104). Admittedly, the system embodied a limited set of choices for a very simple
‘world’, and its impressive success depended on extensive restrictions on
its design (cf. 10.73, 88).
10.33
Winograd's next book adopted a much wider scope by covering a whole range of
possible designs and systematically considering them in relation to ‘the major
directions in linguistics’ (LC 3). Although ‘the study of linguistics may be
as old as language itself, and current linguistic science can trace its origins
back at least as far as the Sanskrit grammarians’, Winograd picks out some
‘major turning points at which the focus of study changed and linguists felt
they had finally arrived at the "real" Issues of language’ (LC 6).
If we follow ‘the philosophy of science’ rather than the ‘popular view’,
we see that the ‘history’ of a ‘science’ does not manifest a ‘linear
progress’ of ‘theories’ ‘getting better and better, explaining more
phenomena, making more accurate predictions, and becoming more elegant’.
Instead, ‘the scientist is faced with a complex interconnected world’ and
has to ‘select the questions to be asked’ and ‘determine what kinds of
answers will be considered acceptable’ (LC 6f) (cf. 13.1).
10.34, Periods of normal science’ show
‘widespread agreement’, and ‘the foundations’ and ‘basic
assumptions’ ‘are taken for granted’ (LC 7). ‘Science in this state’
is ‘operating within a paradigm’, i.e., a ‘social
structure’ and a ‘conceptual framework’ ‘of methods and biases about
what deserves study and how it can be described’ (LC 7, UN ix, UC 24).
‘Progress’ consists in ‘the details of the theories’ being ‘worked
out’, while ‘problems that cannot be explained within the current
paradigm’ are ‘ignored, or excuses are found’ (LC 7). ‘But gradually, as
the current phenomena become overstudied, more
scientists move toward the difficult areas, and the shortcomings of the whole
framework’ become ‘apparent’. ‘Finally’, ‘a radically different
paradigm’ is proposed to supplant ‘the current standard’, and a ‘heated
debate’ ensues. Though most attempts to establish new paradigms’ are
‘rejected’, ‘a few’ ‘revolutions’ are ‘successful’, because the ‘difficulties of
the old theories are eliminated’ and ‘areas previously unexplored are now
opened’. In return, ‘old issues appear to be less relevant’ and are
‘dropped from consideration’. ‘The new paradigm becomes normal science’,
enters, positions of academic power’, ‘gets formalized into textbooks’,
and persists until ‘the cycle is repeated’. Because ‘practitioners’ are
‘rarely’ ‘converted’, ‘the cycle’ typically requires ‘enough time
for younger scientists to replace the old establishment’ (10.103).
10.35
Thomas 5. Kuhn (1970) ‘used the so-called "hard sciences" as his
examples’, e.g., ‘astronomy, chemistry, and physics’, but his ‘concept
of scientific revolution applies even more convincingly in the "human
sciences", such as psychology, linguistics, and sociology, where the
revolutions are more frequent and radical in throwing away all that came before,
and where there are few technological applications’ as a ‘measure of
progress’ (LC 8 cf. UN ix; 10.106; 13.4). There, ‘a scientist looking for a
new paradigm is strongly affected by the other sciences currently enjoying
successful development’ (LC 8). ‘Either consciously or unconsciously, these
are viewed as a model’, leading to ‘a metaphorical imposition of their
ideas’. ‘Linguistics’ ‘has been especially open’ to ‘using the hard
sciences as bases for analogy’ in this fashion (cf. 13.11).
10.36
Winograd accordingly proffers a ‘survey of linguistic history’ as ‘a
series of metaphors’ (LC 8). The
oldest ‘metaphor’, and still ‘the predominant view’ ‘in our
society’, is ‘linguistics as law’ (LC
9). ‘Prescriptive grammar’, though ‘long rejected by scientists
studying actual language use’, envisions ‘a set of rules that must be
followed’ in order to gain a ‘place in the social structure’ (i.a., cf.
4.5f, 86; 8.4).'The main concern’ Is ‘correctness or purity of the
language’, and ‘the linguist is to act’ ‘as judge and policeman’.
‘Current theories of linguistics reject this metaphor’ and refuse to
‘fight’ ‘evolution’ or to ‘force the conventions of one social class
onto the rest of society’. Even so, Winograd allows that "'correct
grammar"‘ might help ‘people’ ‘to function within the social
structure’, and ‘a practical theory of linguistics can provide a basis for
language teaching’ (LC 9, 26f). His book says nothing about how this could be
done, but it is the only one in my survey to comment upon constructions that
have traditionally bothered English teachers and purists: ‘split
infinitives’, ‘dangling prepositions’ and "who"/"whom''‘
distinctions’ (LC 249, 481, 245) (cf. 3[51).[101
10.37
‘In the nineteenth century, a paradigm for linguistics’ was provided by ‘comparative
philology’ (LC 9) (cf. 2.5f. 6.5; 8.6, 15, 40; 12.20, 90f). The metaphor
here was ‘linguistics as biology’, ‘in the style of natural history’,
notably ‘Darwin’s theory of evolution’ (8.6; 12.17). ‘Just as biologists
developed taxonomies of organisms’, ‘linguists’ used ‘comparisons of
structures’ to ‘classify’ ‘data into a complete phylogenetic tree’ of
‘languages’ (LC 9f) (2.5; 4.73; 12.91). This work illustrated the
‘puzzle-solving activity’ common’ in ‘normal science, with ‘pieces’
being ‘fitted together’ as proof of ‘being on the right track’ and of
‘progress being made’. Gradually, ‘philologists’ ‘exhausted the body
of well-known languages’ and, turned to more remote languages reported by
anthropologists’. But enthusiasm waned as ‘cataloguing’ became
‘tedious’ and ‘few satisfying general principles were discovered’.
10.38
The next ‘revolution’ ushered in ‘structural’
or ‘descriptive linguistics’,
accompanied by, a shift of focus from the family of languages to the structure
of the single language’ (LC 10f). ‘This paradigm’ ‘was, strongly
influenced’ by ‘behaviourism’, which ‘dominated American psychology’,
insisted on ‘objective scientific experiment’, and abjured all reference to
‘mental processes’. Even though behaviourism arose from animal biology,
Winograd diagnoses the dominant metaphor to have been ‘linguistics as chemistry’
(cf. 13.12). ‘The analysis of language data was modelled after a
positivist view’ of how to use ‘experimental techniques to rigorously
determine underlying structure’, just as ‘a chemist’ ‘determines the set
of molecules’ in a ‘complex substance’ and the ‘basic elements’ In
‘those molecules’ (cf. 5.28). ‘The analogy to chemistry is closest in the
way sounds are organized into words’ (cf. 7.16). ‘Every language has a mall
set’ of ‘phonemes’ amenable to ‘discovery procedures’, even for ‘a
language not known to the scientist’ (13.26). But ‘the set of meaning
elements or morphemes in a language is much larger and less well-structured’,
and ‘the same methods’ were even ‘less satisfying’ ‘in the study of
syntax’ (13.27f). Nonetheless, ‘many different languages were described’
within ‘as wide a range as possible’, including ones ‘outside modern
Western society’, again with the aid of ‘anthropologists’ (5.2).
10.39
Next came the ‘generative’ paradigm:
‘linguistics as mathematics’ (LC
11) (7.44- 13.15, 17f). ‘Empirical methodology’ was ‘rejected’ and
‘observable behaviour’, was neglected in favour of ‘the intuitions of
native speakers’, their ‘tacit knowledge’, and ‘the underlying
faculty’ to ‘create and understand sentences’ (7.14, 24f). This ‘theory
must postulate mental structures and processes’ in absence of ‘techniques
for observing what goes on in the mind of the language user’; yet ‘Chomsky
argued that, linguistics could study the abstract mental structures without
indulging in unprovable speculations’ (LC 12) (cf. 7.10, 15, 27). His notion
of ‘competence, an abstract characterization of a speaker's knowledge of a
language’, is ‘closely related to the notion of proof in mathematics’.
‘We can think of mathematics as a "language" of formulas’,
‘symbols’, ‘axioms, and rules of inference’. ‘Mathematics is not the
study of how people invent such expressions or what goes on in their minds then
they read or try to prove them’. Rather, ‘its goal is to produce a set of
rules and formal mechanisms that precisely determine which ones are true. The
measure of success for axiomatization
(laying down the rules and operations)’ ‘lies in elegance and economy’.
Similarly, ‘generative linguistics views language as a mathematical object and
builds theories’ ‘very much like sets of axioms and inference rules’. ‘A
sentence is grammatical’ if ‘some derivation’ ‘demonstrates that its
structure is in accord with the set of rules, much as a proof demonstrates the
truth of a mathematical sentence’ without ‘describing how a mathematician
sets out to generate’ a ‘proof’.
10.40 The final
‘paradigm’ in Winograd's history is his own, the ‘computational’
one, with its metaphor coming from the ‘computation’ done with ‘stored
program digital computers’ (LC 13). ‘The computer shares with the human mind
the ability to manipulate symbols and carry out complex processes’, but its
‘workings are completely open to inspection and study’ and to ‘experiments
in building programs, knowledge bases’, and ‘precise’ ‘models of mental
processing’ (10.5). Therefore, ‘we can try to explain the regularities among
linguistic structures as a consequence of the computations underlying them’
(13.31).
10.41 Winograd's history
ends with no indication of whether and how far this latest paradigm has
displaced the ‘structural’ and ‘generative’ ones, as a Kuhnian viewpoint
would suggest it must have done. Instead
of the absolute rupture wherein the science ‘throws away all that came
before’ (LC 8; 10.36), Winograd prefers to absorb and conserve, thereby making
the book more suitable for ‘graduate work’ ‘in linguistics’ (LC vii) --
with the specific objective, I think, of retraining linguists for jobs in the
computer industry or at least for joint research with computer scientists. [11]
He concentrates not on how the earlier paradigms may have led to crisis and
stagnation, but how they might be made computationally feasible. He merely
notes, without trying to adjudicate, the many ‘debates’ arising in
linguistics over generative transformational grammars (LC 133, 152, 166, 170,
173, 182, 188, 233, 319, 557, 563, 572, 574, 582).
10.42 The book therefore
pursues a delicate compromise. The opening chapter promises ‘a book about
human language’ ‘as a process of communication’, ‘motivated’ by the
‘questions’ like ‘what knowledge must a person have to speak and
understand language?’ and ‘how is the mind organized to make use of this
knowledge in communicating?’ (LC 1). But
most of the book sidesteps these questions by simply collapsing the distinction
between natural and formal languages and presenting, on fairly even-handed
terms, a wide array of ‘grammars’ from linguistics, mathematics, algebra,
automaton theory, and computer programming. A substantial level of formality and
abstraction is maintained, and commentary and criticism are couched more in
computational terms than in linguistic ones. Winograd serenely hopes that ‘in
long run the technical material presented’ ‘will retain its usefulness’ by
‘fitting in new ways into our interpretation of language as a human
phenomenon’ (LC ix) (cf. 11.5).
10.43 A deft though tricky
manoeuvre is to draw the borderlines in just such a way as to include
computation and standard linguistics and to exclude other fields of concern,
including some raised before in UN. Winograd now sees a ‘high degree of
commonality between the "generative"‘ and
‘"computational" paradigms’, and suggests ‘they may be seen as
two variants of a single "cognitive paradigm", (LC 20). He admits the
computational side disagrees when it maintains that ‘the structure of language
is to be derived from the structure of processes’ (versus the division of
‘competence’ from ‘performance’)[12] and that ‘the knowledge
structures and processes for dealing with language are to a large degree shared
with other aspects of intelligence’ (versus the ‘distinct language
faculty’) (LC 21, 151, 186f) (cf. 7.12, 26). But he says these
‘differences’ are contained ‘within an ‘overall area of agreement': that
‘the proper domain of study is the structure of the knowledge possessed by an
individual’, and that ‘this knowledge can be understood as formal rules
concerning structures of symbols’ (LC 20, 273).
10.44
Winograd does seem uncomfortable about the term ‘cognitive’, using it rarely
in the book and mainly in connection with the aspirations of generative
linguistics (LC 133, 149, 164, 175, 177, 186), plus the approach that simply
seized the term by calling itself ‘cognitive grammar’ (cf. Lakoff and
Thompson 1975) (LC 252, 311, 578). ‘Cognitive psychology’ gets just one
mention, in regard to a trite finding of list-learning research (primacy and
recency effects) (LC 505). Even in the 1986 volume, ‘cognitive psychology’
is anachronistically charged with admitting only ‘well-controlled stimuli’
and ‘patterns of recurrence’ in ‘experiments with rats in mazes, nonsense
syllable memorization’ and the matching of geometrical figures’ (actually,
concerns already on the wane in the 1960s), and with neglecting ‘models of
memory, attention and inference’ (UC 114, 25). That Winograd was simply
unaware of research like that surveyed in Ch. 11 is hard to Imagine. More
likely, he saw a potential threat first to the generativist outlook preserved
here In LC, then to the phenomenological one adopted in UC.
10.45
The ‘principles’ Winograd enunciates for the ‘cognitive paradigm’ again
accord with generative linguists in rejecting the ‘primary’ status of
‘social interaction’ along with ‘the text itself as the central focus’
(LC 20) (cf. 9.3; 10.81; 13.20). This move marginalizes both the Hallidayan
‘systemic grammar’ used earlier in UN and the ‘phenomenology’ advocated
in UC (cf. LC 21, 273, 278f), as if his own most characteristic work were
somehow outside the ‘cognitive paradigm’ even though it filled an issue of Cognitive
Psychology (11.2). When expounding its
‘relevance to the study of language as a cognitive process’, Winograd does
grant ‘systemic grammar’ a ‘deep cognitive significance’ and
contemplates ‘pushing’ it ‘into the cognitive or [!] generative
paradigm’ by ‘moving to a mechanically applicable rule system’ (LC 280),
but no such step is taken. The prospects are blurred even more when he decides
that ‘the phrases "computational" and "cognitive
processing" will be used interchangeably’, the one for ‘computational
details’ and the other for ‘the general approach to modelling human
language’ (LC 22). Surely this correspondence is precisely what needs to be
firmly established (cf. 7.78; 13.45).
10.46
Incongruously, the ‘basic model of communicative processing’ in the opening
chapter features ‘communicative goals’, ‘effects to be achieved,
information to be conveyed, attitudes to be expressed’, and ‘actions’ and
‘reactions’ to be ‘caused’ ‘on the part of the ‘comprehender’ (LC
13) (cf. 10.97f). ‘The producer must map this multi-dimensional collection of
goals onto a sequence of sounds’ or ‘marks’ (LC 14). Aside from ‘tone
and vocal gesture the message is forced into a linear form’; ‘a variety of
mechanisms’ ‘merge multiple messages into a single structure that enables
the comprehender to perform the reverse process, inferring the original goals
and messages from the information received’ (cf. 7.83; 10.18, 47, 65; 11.15,
81; 12.47, 13.57). Hence, ‘language provides’ ‘information
resources that can be manipulated by the producer: the choice of words, the
structure of phrases, and the patterns of emphasis producer and intonation’
(cf. 9.34, 37, 12.43, 72; 13.24). Of course, ‘communication’ is,
reflexive’, because ‘the design of an utterance depends critically on the
producer's expectations’ about ‘the comprehender's’ ‘knowledge of the
language’, ‘the world’, and ‘the situation’ (LC 14f). All these
precepts resemble those of UN far more than those of the rest of LC (cf. 10.9f,
12, 23ff 26, 29).
10.47 ‘Most work’ in
‘linguistics’ is ‘on spoken language, since it is more fundamental than
written language’, and Winograd's ‘basic model’ follows suit, even though
‘most computational models deal only with typewritten character sequences’
(LC 15, 13; cf. 10.50). The ‘model of processing’ offered as ‘a first
approximation’ ‘when an utterance is heard’ foresees ‘sound patterns’
being ‘created’ and ‘then analysed to produce syntactic structures, which
are in turn used to form appropriate representations’ (LC 15f). ‘The
production of an utterance’ ‘goes in the opposite direction -- from
representation to syntax to sound’ (LC 16). ‘This general model
corresponds’ to that of ‘analytic philosophers of language drawing on ideas
dating back to Aristotle and beyond’. However, the model, is, distinguished’
by, its focus on the description of processes that explicitly manipulate formal
structures’ -- a ‘central’ ‘idea’ for ‘a11 areas of computer
science’ and thus also for ‘the computational paradigm’ of ‘linguistic
description’. ‘Artificial intelligence’ in particular makes the ‘basic
assumption’ that the ‘representations operating in mental processes’
‘can be formally described as data structures like those of a computer’ (LC
15) (cf. 10.4, 24, 30, 69. 73, 76-79).
10.48
In another manoeuvre congenial to linguists, the ‘traditional’ way of
‘representing’ ‘linguistic structures’ in ‘formalisms corresponding to
different levels of structure, such as
sounds, words, and phrases’, is said to reflect ‘a natural series of levels
common to all human languages’ (LC 16) (cf. 4.71; 5.34f. 7.45; 8.51f- 9.30;
13.29). Equally welcome is the idea that ‘the organization at each level is to
some extent independent of how it relates to the levels around it’ (cf. 10.51;
13.27). ‘This stratification is a
natural organization for any complex mapping process’ ‘into stages, each of
which is simple’ (cf. 9.30- 13.57). ‘Computational models are also based on
the, idea that a complex process can be decomposed into a collection of simpler
processes, each operating to some extent independently’. ‘The advantage of modularity’
is that ‘the system is flexible and expandable’, and ‘the effects’
of ‘changes’ ‘can be localized’ (cf. 10.9). ‘Integration of the
levels’ remains feasible If we have ‘a uniform definition for the structures
that the components accepted as inputs and produced as outputs’ (but cf.
10.8f). Winograd thus obtains ‘a simple stratified model of language
comprehension’ (with ‘production’ ‘operating in the opposite
direction’), in which ‘the knowledge of language is made up of rules for
manipulating different levels of structure’ (LC 16f) The model looks like the
usual linguistic level scheme, except for the added component of ‘reasoning’
running on ‘deductive’ and ‘inferential rules’.
10.49 Winograd concedes
‘this model is wrong in its suggestion that levels and processes can be
separated’, but ‘the simplification’ ‘has served as a basis for the
design of computer systems’ and ‘psychological models’ (LC 17). Also, the
lines and arrows In the model suggest that each level interacts only with
adjacent ones by ‘operating with the results of the one above It and producing
structures for the one below it’, which does not always work, e.g., for
‘stock phrases or idioms’ ‘related directly to meaning’ rather than
‘analysed’ into ‘syntactic structures’ (LC 17, 19) (cf. 2.61; 4.60;
5.32, 54; 7[34]; 9.93; 13.28). Indeed, any model ‘depicting the understanding
process’ as a ‘strict sequence’ of ‘stages’ is ‘wrong’ (LC 19).
‘Many experiments have demonstrated that in listening to speech we often use
knowledge of the expected meaning’ to ‘analyse the sounds’ and ‘decipher
the words’ (LC 19f) (11.77; 13.57). Moreover, ‘a system organized in
sequential stages is "brittle": ‘a problem at the beginning’ can
make ‘the whole process break down’. So we should ‘increase the
flexibility’ by ‘separating the processing sequence from the structural
levels’. ‘We can think of the assigned structures all being written on a
blackboard and the component processes’ (or ‘knowledge sources) reading’
from it or writing’ on it; ‘a process’ is ‘not limited to reading only
what was written by its upper neighbour’, but can use any, information’
‘available’.
10.50
Yet ‘since the simpler stratified model has been the most developed, much of
the material presented in the book’ is ‘based on it’ (LC 20). ‘In
particular, most of the material on syntax will assume’ ‘a separate
component called the parser, which
operates on words that have already been recognized and found in a dictionary,
and which produces syntactic structures for use in a separate phase of semantic
analysis’ (cf.10.10, 21, 47, 11.33f, 77; 13.32). The ‘advantages and
problems of increasing intercommunication’ ‘in a non-stratified process
model’ are viewed as a topic in ‘current research’, but aired only briefly
for ‘stratificational’ and ‘systemic grammar’ (LC 20, 299-303).
Otherwise, most ‘interactions’ are either ‘left ‘implicit in the
rules’ or seen as potential ‘complexities’ and ‘difficult to control’
(LC 151f, 305, 310, 389).
10.51
Readers of Winograd's dissertation may be amazed (I was) to find him now calmly
‘adopting the classical linguistic method of studying syntax independently’
(LC vii) (cf.10.20). This manoeuvre is justified by pointing to the ‘broad
self-contained literature on syntactic theory and technique that needs to be
mastered before the Interaction between syntax and meaning can be understood’
(LC viii). Winograd professes no ‘theoretical
commitment’ to ‘the autonomy of syntax
hypothesis’, which postulates, a relatively independent body of phenomena
that can be characterized by syntactic rules without considering other aspects
of language or thought’ (LC vii, 21, 151) (7.57- 9.2). ,To interpret
the ‘hypothesis’ ‘as a belief that meaning is unimportant in the study of
language’ is dismissed as a ‘mistaken caricature’ (LC 151), though
Chomsky's own gibe that meaning is no more relevant than ‘the hair color of
speakers’ (SS 93; 7.56) hardly leaves room for further caricature. For
Winograd, at any rate, ‘the essential claim is that an analysis of the
structure of language’ ‘will be best achieved by finding the structure of
each component separately and then understanding their interactions (LC 151).
‘A complex system’ can be ‘treated’ as ‘nearly decomposable’ by
assuming that ‘the interactions among components are much less crucial than
the independent functioning within each one’ (LC 152). ‘Having thus
dismissed (for the time being) questions of linguistic processing’, ‘sound,
and meaning, the linguist can ask "what is the nature of the syntactic
structure of a language?"‘
10.52
No doubt these moves are steered by the pressures of composing a separate volume
on ‘syntax’. In practice, however, the volume continually refers to
‘correspondences’ between the ‘syntactic’ (or ‘grammar’,
‘parser’, etc.) and the ‘semantic’ (or ‘meaning’), as well as to
systems that utilize them.[13] Some systems try to go ‘directly’ to the
semantics without any thorough syntactic analysis, such as ‘semantic
grammar’ (Wilks 1973) (LC 51, 260, 363, 374) or ‘conceptual dependency’
(Schank et al. 1975) (LC 74, 318, 367, 402, 405) (cf. 10.1; 11.4, 34; 13.53).
Also, several post-transformational approaches to syntax and grammar have
markedly increased the role of semantics, notably ‘case grammar’,
‘generative semantics’, and ‘Montague grammar’ (LC 180, 185, 257,
311-26, 348, 530, 561, 560-64, 575, 582; MSF 92, 95). Even ‘transformational
theory’, long driven by a ‘subliminal’ ‘desire to reflect meaning’,
now reveals a clear ‘trend to shift work from the syntactic’ ‘to the
semantic component’; and Winograd ends his overview of ‘directions in
transformational grammar’ with the prediction that ‘the theme for the coming
years will be the exploration of semantic formalisms and their integration into
the grammar’ (LC 180, 299, 494, 526, 577f, 581).
10.53
The interaction between semantics and syntax would doubtless have been more
thoroughly treated in the ‘volume on meaning’ so frequently promised in LC
(LC viii, 21, 25, 37, 88, 151, 282, 318, 326, 359, 361, 396, 490, 514, 581).
Winograd planned to cover the following: relations among ‘artificial
intelligence’, ‘philosophy of language’, and ‘pragmatics’; ‘issues
of representation, meaning, and language use’, including ‘quantification and
reference’, ‘the context of action and knowledge’; ‘the, organization’
of ‘discourse’; ‘the use of a data base in semantic analysis’; ‘the
use of frames in representation languages’; the ‘overlap’ of
‘transitivity’ ‘with semantic problems’; reasoning mechanisms’ and,
integrated question-answering systems’; and ‘computer aided instruction’
(UN viii, 318, 151, 361, 514, 282, 21, 396, 326, 490, 37, 359).
10.54
In addition to the postponement of semantics, other ‘limitations of the
approach’ are acknowledged, which ‘to a large degree’ are ‘common to the
computational and generative paradigms, following from the basic cognitive
orientation’ and the view of ‘language as a process going on in the mind of
an individual’ (LC 28). ‘We lose sight of the social dynamics of language
use’ and the, social interaction’, from which’ ‘language’ ‘takes its
meaning’, as well as the ways ‘linguistic devices’ can ‘establish
personal power relationships’ and ‘social distinctions of rank and
status’. We cannot tell ‘why a particular dialect is adopted’ or ‘how
dialect differences play a role’ in ‘group identity and cohesiveness’ (LC
29; cf. LC 181). We discount ‘the central problem’ of ‘language
acquisition’ without which there could be no ‘body of language knowledge’
(LC 19). We do not treat the ‘evocative aspects of language’ in ‘the
tradition of a culture’, such as ‘the emotional dimensions’ of
‘literature’ (LC 29). We pass over the ‘historical aspects of language’;
‘though all change takes place as a result of language acts by individuals,
the relevant patterns are not visible at that level’ (cf. 2.45; 3.57; 4.81,
4[6]). And finally, we do not consider ‘the social effects’ and
‘political’ impact of ‘applications’, e.g. of ‘creating computer
therapists or judges’ (LC 29f).
10.55 Moreover, ‘for the
most part the book does not deal with specific applications or the problems’
of ‘making practical use of linguistic theories’ (LC 22) (13.60).
Nonetheless, Winograd briefly reviews the issues. First and foremost, naturally,
is the ‘major goal’ of ‘current linguistics’ to describe language with
the formality and precision needed for
computer implementation’; prospects of ‘resources’, ‘support’ and
('Air Force’) ‘funding’ are raised. Reciprocally, ‘the computer has
opened many new possibilities for linguistics’ and enabled ‘the development
of specialized artificial languages’ (LC 22f). ‘Machine translation’,
which has ‘focused on the syntactic structures of language’ and on
‘computer forms’ for ‘bilingual dictionaries’ and which has not been
‘successful’ in ‘fully automatic high quality translation’, has now
sparked ‘renewed interest’ (LC 23, 358f, i.r; but see 10.106). Further
domains of, cf. UN 41f; ‘human-machine interaction’ ‘in natural
language’ include ‘information retrieval’ (for ‘a "library of the
future"‘), ‘text retrieval’, ‘question answering’,[14]
‘explanation systems’ , ‘expert systems’ , and ‘speech understanding
systems’ (i.e. ‘converting spoken sounds to written text)’, along with
‘text analysis’, ‘knowledge engineering’, ‘natural language’
‘front ends’ ('the interface seen by a user of a computer system’) ‘for
data base systems’, ‘computer aided instruction’, and ‘aids to text
preparation’ such as ‘word processors’, ‘spelling checkers’, and
‘dictation systems’ (LC 23-26, 359-61).
10.56
In addition, the ‘potential’ of ‘the computational approach to language’
-- this time ‘shared with’ ‘structural and generative linguistics’ --
extends to such ‘practical aspects’ as ‘psychology’ (compare
‘psycholinguistics’), ‘language therapy’ for ‘deficits’ and
‘aphasia’ (compare ‘neurolinguistics’), ‘effective communication’
(compare ‘rhetoric’, ‘general semantics’, and ‘preservers of the
"purity" of language"‘, all three ‘not held in high regard by
academic linguists’), ‘designing languages that are easier to understand and
learn’ (compare ‘Esperanto’), ‘teaching language skills In elementary
and secondary schools’, and ‘teaching’ ‘translation’ to ‘humans’
(LC 26ff). These listings resemble Halliday's, who is in fact cited (LC 27; cf.
9.111), just when Winograd was de-emphasizing ‘systemic grammar’ for not
being a properly ‘cognitive approach’ ‘rooted’ in ‘mathematics or
formal logic’ (LC 273) (cf. 10.39, 45). Curiously sanguine too is the idea
that ‘cognitive linguistics’ as ‘a theoretical framework for dealing with
grammatical complexities’ could enable us to ‘understand how language
works’ and thus bring us ‘a long way toward understanding how the rest of
the mind works in reasoning, learning, and remembering’ (LC 27f) (cf. 13.21f).
10.57 As
if in compensation for the various exclusions and limitations, the concept of
‘syntax’ expands far beyond Winograd's definition, namely ‘the part of
linguistics that deals with how the words of a language are arranged into
phrases and sentences and how components like prefixes and suffixes are combined
to make words’ (LC 35; cf. LC 11). Instead, the term subsumes the construction
and organization of every class of formal symbol system. Winograd's presentation
of formalisms and grammars resembles Pike's treatment of the physiology of
utterance in two ways: its monumental thoroughness, and its uncertain relevance
for essential qualities of human language (cf. 5.44). ‘Much of the material’
is ‘an explanation of techniques for structuring data and program in
computers’, designed ‘to develop the student's mastery of the concepts of
computational processing’ (LC 13). These ‘techniques’ are offered not as
‘precise theories of human language use, but rather building blocks from which
theories can be constructed’.
10.58
Accordingly, we are painstakingly shown the qualities and uses of
‘grammars’, ‘patterns’, ‘schemas’, ‘registers’, ‘records’,
‘agendas’, ‘stacks’, or ‘buffers’. We find out about ‘rules’,
‘predicates’, ‘categories’, ‘classes’, ‘elements’,
‘variables’, or ‘variants’. We watch the construction of ‘charts’ or
‘tables’ with ‘edges’ and ‘vertices’, of ‘networks’ with
‘states’ and ‘arcs’, of ‘trees’ with ‘nodes’ and ‘leaves’,
and of ‘roles’ with ‘slots’ and ‘fillers’. We are initiated into the
issues of ‘computational implementation’, such as ‘system engineering,
compiling’, ‘bookkeeping’, ‘pattern-matching’, ‘nesting’, ‘arc
ordering’, ‘backtracking’, and ‘automatic emptying’, along with
‘classification’, declaration’, ‘invocation’, ‘enumeration’,
‘activation’, ‘deactivation’, ‘iteration’, ‘continuation’, and
‘termination’. We see numerous ‘figures’ for ‘procedures’ to
‘test’ or ‘match a pattern’, and to ‘recognize’, ‘generate’, or
‘parse a sentence’ by means of a ‘network’, ‘chart’, or ‘tree’
-- and even to ‘create a grammar’.
10.59
And a bouquet of grammars gets unfolded. The main types treated are context free
grammars’, ‘transformational grammars’, ‘augmented transition network
grammars’ and ‘feature and function grammars’ (this last type including
‘systemic’ and ‘case’ grammars). These types differ both in the
notations used and in the ‘general issues’ of ‘design’ for applying them
as programs, e.g., ‘formal power’, ‘uniformity of processing’,
‘separation’ ‘of levels’, or ‘flexibility’ versus ‘precision’
(LC 89f, 114). Already for ‘purely syntactic, uniform, precise, context-free
parsing’, ‘strategies differ’ along ‘three major dimensions': (a) ‘parallel
versus sequential treatment of alternatives’, i.e. ‘keeping track’ of
them ‘simultaneously’ versus ‘trying’ just one and ‘backtracking when
its choices lead to failure’, (b) ‘top-down’
or ‘goal directed processing’ ‘versus bottom-up’
or ‘data directed processing’, i.e. ‘looking at rules for the desired
top-level structure (usually a sentence) and seeing what constituents would be
needed’, versus ‘beginning with the words’ and trying to ‘combine’
them into a ‘constituent’;[15] and (c) ‘systematic’ ‘choice of nodes
to expand (in a top-down procedure)’
‘or combine’ (in a bottom-up
procedure’), either in a ‘directional’ manner, ‘moving’ ‘in one
direction (usually left to right)’, or in a ‘size-oriented’ manner,
‘taking chunks of increasing size’, or in a ‘mixed’ manner doing some of
both (LC 90f) (cf. 11.13, 19, 25, 32, 55, 59, 73, 77, 79, 13.44).[16]
10.60
As these ‘dimensions’ indicate, a computational framework allows more
elaborate and operational comparisons between grammars than do other frameworks.
We can see this clearly in the comparison between ‘transformational
grammars’, which ‘take the process of abstract derivation as a starting
point’, and ‘augmented transition
network (ATN) grammars’, which ‘take the process of parsing’ and put
It in ‘the clearest formulation’ (LC 195). ATNs ‘are currently one of the
most common methods of parsing natural language in computer systems’ and have
‘served as the basis for psycholinguistic theories and experiments’. The
‘formalism is clear enough to be grasped and followed easily’, yet can
‘deal with complex phenomena’ (LC 196). ‘Instead of’ ‘rules’,
we have ‘labelled networks’ in
which ‘each’ is labelled with a word, a lexical category, or a syntactic
category’. In a ‘simple
transition network, an arc whose label is a word or lexical category can be
traversed if it matches a single word of the Input’. But we can make the
‘network’ ‘recursive’ by using
‘composite syntactic categories’ as ‘labels’; then ‘the arc is
traversed by matching a sequence of input symbols’, and ‘a network’
appears within the ‘network’; for example, we could have ‘an arc labelled
NP’ to ‘recognize’ the entire, ‘constituent’ of a noun phrase (LC
197). Hence, we can ‘adapt a schema from grammar rules to networks’; the
method of ‘choosing a rule’ and testing whether’ it ‘spans a contiguous
sequence of constituents’ ‘is replaced by choosing an arc’ and ‘testing
whether a network accepts a contiguous sequence of constituents’ (LC 199).
10.61
‘Augmentation’ is the technique of
‘adding conditions and actions
associated with the arcs of a network’ (LC 204). ‘The conditions restrict
the circumstances under which an arc can be taken’, e.g., by stipulating
‘special properties of the word or constituent to be matched’ or of the
‘constituents that have already been found’; the ‘actions perform
feature-marking and structure-building operations’ (LC 204f, 208).
‘Conditions and actions make use of registers’, ‘each having a name and storing some information’,
such as, roles and features’. ‘Whenever an arc Is taken, the associated
action is carried out, causing the contents of registers to be set’ (LC 208).
‘A configuration’ is a
‘temporary structure’ that ‘includes the register table for the
constituent being built, along with the current network, state, and position’
(LC 210).'As with other syntactic formalisms’, ‘ATNs’ have ‘a
"basic theory" and then an ever-growing collection of changes and
extensions’ to ‘cover more of the data’ (LC 244). 'For practical uses’,
‘one picks out a subset of structures’ to ‘handle and simply ignores the
others’, ‘hoping’ ‘the subset will be "habitable"‘ and
‘convenient to converse with’ (LC 245).
10.62 Through ‘the use of
registers’ in ATNs, ‘features’ can be ‘associated with whole networks’
and need ‘not appear in the dictionary’, whereas, transformational
grammars’ ‘add special grammatical markers’ and ‘have them manipulated
by transformations’ (LC 210, 216; cf. 7.63f, 72). Also, ‘the ordering or
conditions and actions’ in ATNs can do ‘the same work as the ordering of
transformations’ in a ‘cycled’ (LC 220, 229). ‘In an ATN’ grammar,
‘the parser will work left-to-right and top-down’, so ‘the action that
sets a register will affect’ only ‘conditions on arcs to the right’. This
design ‘removes flexibility’, e.g. by impeding ‘bottom-up’ operation’,
but in return offers ‘a relatively simple and elegant way for the interactions
between different syntactic phenomena’, e.g. ‘subject-verb agreement’ and
‘passive voice’ (LC 220, 222). Hence, ‘phenomena’, related to the
rule-ordering mechanisms, in, transformational grammar’ get treated in, a
somewhat more natural’ manner, ‘since the order is imposed by the order of
the phrases in the sentence rather than by a less Intuitively guided choice of
ordering for derivation rules’ (LC 222; cf. 7.54). Finally, ‘global hold
registers’, which ‘belong to the sentence being parsed as a whole’ and are
‘expanded and contracted as nets are entered and left’, can keep ‘items on
hold’ until needed, and thus handle ‘long-distance dependencies’, ‘one
of the most complex phenomena of syntax’ and ‘a major motivation for many of
the mechanisms of transformational grammar’, e.g. the ‘movement
transformation’ (LC 232ff).
10.63
Comparing grammars this way on computational grounds illustrates the operational
criteria entailed in choosing and designing a grammar (13.31). In general,
‘scientists’, including ‘linguists’, ‘are motivated to find’
‘simpler’ ‘explanations’ (LC l84). But computationally, the striving for
‘simplicity’ can involve disadvantages in regard to ‘power’,
‘efficiency’, ‘effectiveness’, ‘precision’, ‘appropriateness’,
‘selectivity’, ‘ambiguity’, and ‘arbitrariness’ (cf. LC 73, 108,
361, 526, 326, 371, 75, 323, 532). For instance, ‘context free grammars’
have been ‘widely used because of their simplicity’, but cannot ‘handle
the full complexity of natural language’ (LC 72, 361, 383, UN 42) (cf. 7.48,
73f. 13.39). Like ‘phrase structure grammars’, they can work only on some
‘simplified subset’ of English’ and must ‘lose simplicity’ to ‘gain
power’ (UN 42, LC 73). ‘Simplicity’ also enhanced the appeal of the
transformational approach (7.36f, 40, 50f) and has been a motive for various
revisions, but has played a very ‘mixed role’ in ‘the generative grammar
literature’ (LC 148, 162, 173, 319, 168, 578, 183). Theorists called for a
‘specific and restrictive formalism’, yet these ‘are generally also more
complex’ (LC 183f, 175; cf. 7.22, 66, 94). Studies of ‘psychological
reality’ showed that the measure of ‘simplicity’ and ‘complexity’ in
terms of ‘number of transformations’ of a, sentence’ did not fit the
observed ‘ease of comprehension’ (LC 177f). The idea that a ‘language
learner, like the scientist, prefers parsimony’ and ‘simplicity’ has also
failed to produce ‘precise measures’ (LC 184).
10.64 So
Winograd proposes further ‘desiderata’ for ‘choosing among competing
grammars’ (LC 327). First, ‘correspondence
with meanings’ is essential to ‘mathematics and programming
languages’, and, as we saw (10.52), is frequently invoked despite the book's
overriding concern with syntax. Second, ‘perspicuity’
is attained for a grammar by making ‘the facts it expresses about language
directly visible in the form’. The ‘consequences’ of ‘a transformational
rule that moves an abstract marker’ in ‘a tree structure’ ‘are implicit
in its interactions with other rules’ and ‘may be incomprehensible on
inspecting the rule’ (cf. Woods 1970) (LC 327, UN 45) (cf. 10.19, 67). In
contrast, in ‘context-free grammars’ ‘every rule is also a pattern’ (LC
327). ‘Recursive transition networks’ have the same ‘transparency’
‘every path through the arcs’ is ‘a pattern of constituents’; but this
‘perspicuity is no longer guaranteed’, when ‘augmentations such as
conditions, actions, and registers are added’. ‘In systemic grammars’,
‘the effects of particular realization rule can be seen as a direct statement
of the form of the constituent to which it applies, but because the rules can
interact’ they are less ‘perspicuous’ than ‘context-free rules’.
‘Functional grammars’ are now ‘returning to simpler rules which are more
immediately structural’.
10.65
Third, ‘nondirectionality’ is
attained by ‘using the same set of rules in both the generation process and
the parsing process’ (LC 328) (cf. 10.46; 13.57). ‘Simple patterns and
context-free grammars’ are ‘neutral’ in just this way. But ‘a
transformational grammar "runs" only in the direction of generating
and is quite difficult to apply’ to ‘parsing’, it gets bogged down in
‘combinatorial explosion’ because it ‘tries to reproduce the deep
structure of a sentence while doing surface structure recognition’ (Woods
1970) (LC 328, UN 31, 42, 45) (cf. 7.83; 10.21; 11.3, 81).'Simple transition
networks are’ ‘nondirectional’, but in ATNs ‘the’ use of conditions
and actions forces a left-to-right ordering, since registers can be accessed
only after they are set’ (LC 328) (cf. 10.59, 62). ‘Lexical-functional
grammars’ try to ‘modify the ATN formalism to get rid of order
dependencies’.
10.66
Fourth, ‘efficiency’ is attained
by limiting the ‘resources used by a given procedure’, such as ‘time’
and ‘storage’ (LC 114, 111). ‘The theory of computation deals with the
gross order of efficiency': ‘linear, logarithmic, polynomial, exponential,
etc.’ ‘with respect to the length of the input’ (LC 376). ‘In
context-free parsing,’ for example, ‘the maximal efficiency’ is ‘a time
proportional to the cube of the length of the input if the grammar allows
ambiguities or to its square if the grammar is unambiguous’ (LC 114). But this
‘formal efficiency’ ‘is not the same’ as ‘practical efficiency’,
which depends on ‘how the procedure is implemented using particular data
structures in a particular programming language on a particular machine’ (LC
114f). Two ‘implementations’ might be formally ‘equivalent,’ ‘but one
might be tens or hundreds of times faster’ (LC 376).[17] ‘Over the years,’
people ‘have learned to sort out those sources of inefficiency’ ‘due to a
particular choice of how structures are stored or accessed from those’
‘inherent in the type of procedure’ (LC 114). We now have ‘many ways that
procedures can be modified to make them more efficient while producing the same
results’ (LC 109). For instance, we can have ‘the grammar’ ‘compiled’
into another ‘form’ (LC 376) (cf. 10.12, 71). Or, we can ‘set things up so
a particular computation can be done once and used in many places’ (LC 109).
Or, we can insert, pre-computations, in which auxiliary tables or indexes are
created to avoid computation steps as the parser runs’ (LC 115).
10.67
Fifth and finally, ‘multiple dimensions
of patterning’ are needed to cover the various ‘aspects of language
structure’ (LC 328). The ‘dimensions’ concern ‘form’, ‘function’,
and ‘features’ (LC 50, 205, 211, 289, 292). Also, ‘syntactic resources’
are structured along ‘dimensions of organization’, including ‘choice of
items’ ('classification’ of ‘elements’), ‘sequential arrangement’
('grouping’), and ‘function’ ('relation of one element or group to
another’ in terms of ‘roles’) (LC 274f).[18] ‘Transformational
grammar’ gets a low rating here, because the ‘different dimensions’ are
not ‘expressed’ ‘explicitly’, but ‘represented in the structure of the
phrase marker at different points in the derivation’ (LC 328) (cf. 10.19, 62,
64). ‘Systemic grammar’ gets a high rating, however, because ‘constituent
structure is analysed’ in a greater variety of ‘different dimensions’ and,
is described in terms of units that correspond to meaningful elements and that
are less broken up than those of transformational grammar’ (LC 276) (cf.
9.33). Also, ‘since systemic grammar is not centred’ on, formal rules’
(i.e., is not ‘generative in the strong sense’, 10.56), ‘descriptive
structure’ can more easily ‘deal with multiple dimensions of analysis’;
the ‘organization’ of ‘a text’ ‘as a speech act’, ‘a logical
proposition’, a configuration of ‘cohesion relationships’, or a ‘theme
and information structure’ (LC 278) (cf. 9.49f, 55ff, 89-96).[19]
10.68
These desiderata plainly do not coincide to enforce the choice of just one
grammar or formalism, but confront us with trade-offs (cf. 13.1). For example,
ATN grammar and systemic grammar, which Winograd had combined in his own SHRDLU
program, are less ‘perspicuous’ than ‘context-free grammar’, but
superior in regard to ‘dimensions’ and ‘meanings’. Besides, the
formalisms are often ‘equivalent’ enough to mimic each other.[20] For
example, ‘in general it is possible to find ATN correlates of the
transformational constraints without significantly more or less complication’
(LC 244).Thus, criteria of notation and design are inconclusive. The definitive
criterion therefore ought to be the one raised in the first book: in which
system is the ‘operation’ ‘closer to the actual operations humans use in
understanding language’ (UN 43)? But, as we saw (10.42ff), this criterion is
much less central in LC than in UN, apparently to enhance the impartiality of
the discussion and to maintain a cordial alliance with the generativists.
10.69 As
if to make amends, the next book (UC) places so strong an emphasis on human
knowledge and processing that all formalisms are put in question. Already in LC,
Winograd had warned: ‘many critics of artificial intelligence argue that much
of our skill of using language is not in the nature of formal rules’ and that
‘the ability to use language’ cannot be ‘explained by any formal
characterization analogous to data structures of computers or the rules of
formal logic’ (LC 29). His own alliance with those ‘critics’ is signalled
when he refers us to his ‘forthcoming’ book whose ‘theoretical
framework’ ‘explains why the current work on AI cannot provide a basis for
understanding and modelling the full range of human language understanding’
(LC 32). This volume, co-authored with Fernando Flores,[21] who was trained in
management science and had been ‘Minister of Economy and Minister of Finance
in the government of Salvatore Allende’, asserts flat out that ‘one cannot
construct machines that either exhibit or successfully model intelligent
behaviour’; ‘computers cannot understand language’; and, ‘computers will
remain incapable of using language in the way humans do’ (UC xi, 11f, 107).
10.70 To demystify the
computer and to exorcise the ghost in the machine, Winograd and Flores enumerate
the various ‘levels’ upon which a computer might be viewed (UC 86-90).
‘The physical machine’ is a
‘network’ of ‘wires, integrated circuits, and magnetic disks’
‘operating according to the laws of physics’ in ‘patterns of electric and
magnetic activity’ (UC 86f). ‘At the bottom’ are ‘basic elements’ like
‘strands of copper and areas of semiconductor metal’ on ‘wafers of silicon
crystal’. ‘The logical machine’ is composed of ‘logical abstractions such as
or-gates, inverters, flip-flops’, ‘multiplexers’, and ‘address
decoders’; ‘voltages’ serve to ‘represent a logical "true"‘,
or "false''‘. ‘The abstract
machine’ Is a ‘single sequential processor which steps through a series
of instructions’; ‘logical patterns’ ‘of trues and falses are
interpreted as representing a higher-level symbol such as a number or a
character’ (UC 88). ‘Most descriptions of computers’ are at this
‘level’, which is ‘usually the lowest level at which programmer has
control’.
10.71
Next, the ‘high-level language’ is
‘based on more complex symbol structures, such as lists, trees, and character
strings’ (UC 88). ‘A compiler or interpreter converts a formula’ ‘into a
sequence of operations for the abstract machine’, and ‘complex mathematical
operations’ can be done in ‘a single step’. Finally, the, representation
scheme’ ‘uses the symbol structures of a high-level language to
represent facts about the world’ (UC 89). A ‘fact’ can be ‘encoded’
‘as a series of manipulations on a data base or as the addition of a new
proposition to a collection of axioms’ (cf. 10.50). Winograd and Flores stress
‘the complexity that lies between an operation’ in ‘a program’ and
‘the operation of the physical computing device’ (UC 89f). ‘There is no
intelligible correspondence between operations at distant levels’; ‘computer
systems’ ‘can exhibit many levels of representation, each of which is
understood independently of those below it’. However, a more integrated view
is needed to allocate ‘resource use’ in ‘implementation’ (e.g.
‘speed’, ‘storage’) and to handle ‘breakdowns generated by the lower
levels’ (UC 91). ‘Some programmers argue’ that ‘the program should be
written at the level’ where ‘resources’ ‘can be directly described’
(e.g. ‘real time control processes’ ‘in assembly language’), but ‘in
practice, programs are often initially designed without taking into account the
lower level, and then modified to improve performance’.
10.72
Having presented the computer as a ‘tower of levels’, Winograd and Flores
inquire ‘why anyone would consider that computers could be intelligent’, any
more than ‘a clock or an adding machine’ (UC 89, 93) The reason is the
‘apparent qualitative leap’ to "mind-like'‘ qualities’, which is
actually an ‘effect’ of ‘quantitative’ dimensions along which computers
‘differ in degree’ from other machines (UC 95, 93). They have ‘apparent
autonomy’, being able to ‘carry out complex sequences of operations without
human intervention’ (UC 94). They have ‘complexity of purpose’, able to
‘provide’ a wide ‘range of services’. They have ‘structural
plasticity’, allowing us to ‘build mutable higher-level structures’ ‘on
a relatively fixed underlying structure’. And they have ‘unpredictability’
because we cannot know ‘how a program will act short of running’ or
‘simulating it’ (UC 95).
10.73
Or, ‘intelligence’ is attributed because computers can be used for
‘problem-solving behaviour': ‘a process of search for a sequence of
operations that will lead to a solution point’ (Newell & Simon 1972) (UC
95) (cf. 10.5, 10, 30; 11.97f).[22] But for all such cases, Winograd and Flores
argue that the intelligence and reasoning belong not to the computer, but to
those who program it (cf. UC 85, 97, 123f, 131, 165, 178). ‘The programmer’
‘characterizes the task environment’, ‘generates the systematic domain’,
‘designs the formal representation’, ‘sets its structures in
correspondence with the structure available on the computer’, and
‘implements the search procedure’ (UC 96). ‘The computer’ can only
‘operate’ according to ‘the formal representation’ and ‘the rules of
the formal system’ (UC 96f). Whereas ‘the programmer acts within a context
of language, culture, and previous understanding’, ‘the program is forever
limited to working within the world determined by the programmer's explicit
articulation of possible objects, properties, relations’.
10.74
The focus on machine construction and programming forms only one part of a wide
attack on ‘artificial intelligence’ and its projects for ‘natural language
understanding’. Here, Winograd's typical concern for large issues now scales
such heights as to make even Chomskyan universalism seem parochial (cf. 7.18ff).
The new book undertakes to ‘address the fundamental questions of what it means
to be human’, ‘what it means for something to exist’, and ‘what it means
to know’ and ‘understand’ (UC 7, 13, 70, 30, 72, 119). And the answers are
far from what ‘common sense’ suggests (UC 30, 43, 46). An assault is mounted
on the very mainstream of Western science and thought, whose basic views and
assumptions are decried (17 times) as ‘naive’ (UC 8, 30, 40f, 46, 50f, 60f,
69n, 71f, 135, 149).
10.75 Like Winograd's other
books, the latest one is ‘deeply concerned with the question of language’ (UC
17). ‘Linguistic action’ is declared ‘the essential human activity’,
"'the central feature of human existence is its occurrence in a linguistic
cognitive domain"‘ (cf. Maturana 1970) (UC 7, 51) (cf. 10.4, 32, 43;
13.22). The thesis that ‘we create our world through language’ leads to a
‘radical recognition': ‘nothing exists
except through language’ (UC 11, 68) (but see 12.60). Of course, similar
claims have been made for centuries by philosophers (e.g. Heidegger), who tend
to be more at ease with language than with existence, But here, the claim
strategically implies that if computers can't understand language, they can't
understand anything about the world either.
10.76
The chief target of attack is ‘the rationalistic
tradition’, which, emphasizes "information",
"representation", and "decision making"‘, and prizes
‘particular styles of conscious rationalized thought’ (UC 8). ‘This
tradition has been the mainspring of Western science and technology, and has
demonstrated its effectiveness most clearly in the "hard sciences",
those that explain the operation of deterministic mechanisms whose principles
can be captured in formal systems’ (UC 14) (cf. 10.30, 39, 43, 47). It
‘underlies both pure and applied science’ and ‘has greatly influenced’
‘linguistics and cognitive psychology’, plus ‘management theory and
cognitive science’, because it is ‘regarded’ as the ‘paradigm of what it
means to think and be intelligent’ (UC 16). It ‘finds its highest expression
in mathematics and logic’, which ‘are taken as a basis for formalizing what
goes on when a person perceives, thinks, and acts’; and it is deemed
‘self-evident that this is the right or even the only approach to serious
thinking’ (UC 14, 16) (cf. 10.8, 39- 13.15, 17). Winograd and Flores now
propose the ‘tradition’ be, above all in ‘current, re-examined and
challenged as a source of understanding’, thinking about computers and their
impact on society’ (UC 14, 26). They ‘attempt’ to ‘reveal the blindness
it generates’, and ‘argue that’ it ‘needs to be replaced’ ‘if we
want to understand human thought, language, and action, or to design effective
computer tools’ (UC 17, 26).
10.77
‘One cornerstone’ of the, rationalistic tradition’ is a ‘correspondence theory’ of ‘language as a system of symbols’,
composed into patterns that stand for things in the world’ (UC 19, 17) (cf.
10.20, 40, 43).[23] Here, ‘the content of words’ ‘denotes’ ‘objects,
properties, relationships’ ‘in the world’; ‘what a sentence says’ is
‘a function of words it contains’ and their ‘structures’; and
‘sentences say things about the world’, and are ‘either true or false’ (UC
17). ‘More formal studies of semantics’ ‘examining meaning from a formal
analytical perspective’, however, rarely seek ‘formal answers to the
problem’ of ‘correspondence’ (UC 17f). Such ‘questions’ are ‘taken
as unproblematic’ or ‘pushed aside’ as ‘too difficult and open-ended’
(UC 15). Instead, one ‘looks at the relations
among the meanings’ of ‘words, phrases, and sentences’ without
‘reference either to act of uttering the words or to the states of affairs
they describe’ (UC 18).
10.78
‘It is assumed that each sentence in a natural language’ can be matched with
‘one or more’ ‘interpretations in a formal language, such as first-order
predicate calculus’ (UC 18) (cf. 10.8). ‘The study of meaning’ proceeds by
‘translating sentences’ into ‘formal structures’ and applying ‘logical
rules’. ‘Truth theoretic’ ‘systems of rules’ are expected to allow for
‘translating’ without losing the ‘essence of the meaning’, for
‘determining’ ‘the meanings of formulas’ from ‘the meanings of parts
and the structures by which those parts are combined’; and for
‘interrelating the truth conditions for different formulas’ (UC 19) (cf.
‘7.82; 13.18, 59). Naturally, ‘the fundamental’ ‘sentence is the
indicative’ ‘stating that a certain proposition is true; its meaning’
depends on ‘the conditions in the world under which it would be true’ (cf.
9.74).[24] Finally, ‘the meanings of the items being composed should be fixed without
reference to context in which they appear’ (cf. 7.73, 79; 11.2, 36, 40).
Some ‘obvious’, and ‘exceptions’ are ‘recognized’, such as
‘pronouns’, ‘place and time adverbs’, ‘tenses’, ‘but the central
theory of meaning (semantics) deals’ with ‘literal
meaning’, as not context-dependent’ (cf. 12.68).
10.79 In
a similar vein, ‘rationalistic theories of mind all adopt’ some "representation
hypothesis"': ‘that thought is the manipulation of representation
structures in the mind’ (UC 20; cf. UN 3, 23; LC 16, 18, 186; UC 8, 78, 85f,
89, 96). ‘Though not specifically linguistic’, these ‘are treated as
sentences in an "internal language", ‘connected to the world’.
Using a, compatible’, approach’, ‘information processing psychology’
assumes’ that, all cognitive systems are symbol systems’ and ‘achieve
their intelligence by symbolizing external and internal situations and events
and by manipulating those symbols’ with one ‘basic set of underlying’
‘processes’ (UC 25). Hence, ‘a theory of cognition can be couched as a
program’ -- i.e., ‘a formal system’ having ‘variables’ and
‘generating predictions about the behaviour (outputs) of some naturally
occurring system’ ---
which ‘when run in the appropriate environment will reproduce the observed
behaviour’ (10.4, 6). ‘The computer’ ‘enables the scientist to deal with
more complex theories’, and ‘AI’ ‘programs ‘patterned after human
thought and language’ offer a handle on, phenomena that do not have the
obvious limitations of the sparse experimental situations of cognitive
psychology’ (cf. 10.44).
10.80
Winograd and Flores take just the contrary view. They find it ‘naive’ to
think that ‘language conveys information about an independent reality’ (UC
50). ‘Words correspond to our intuition about ‘'reality'‘ because our
purposes in using them are closely aligned with our physical existence in a
world and our actions within it’ (UN 61) (cf. 5.68; 6.12; 8.33; 13.24). ‘But
the coincidence is the result of our use of language within a tradition’. And
‘in using language we are not transmitting information or describing an
external world’ that ‘defines’ ‘the meaning of words and sentences’ (UC
50, 61). Only if we ‘stick to the rather idealized isolated sentences used’
‘in philosophy books’ does it ‘seem plausible to ground the meaning of
words in a language-prior categorization’ (LC 61, MSF 97f). ‘As soon as we
look at real situated language, the foundation crumbles’.
10.81
So we need to emphasize not ‘the mental dimension’ of ‘the cognitive
paradigm’ in LC, but the social, because both language and cognition are
fundamentally social (UC 60f) (cf. 10.43ff, 54; 13.20). To ‘use language’ is
to ‘create a cooperative domain of interactions’ (UN 50, MSF 101). The view
of ‘cognition’ proposed here depends ‘critically’ on the ‘work of
Humberto R. Maturana, a Chilean neurobiologist’ (UC 10, 38).[25] His studies
of ‘visual’ ‘perception’ in primates’ (mainly ‘frogs’) led him to
conclude that ‘the nervous system’ is ‘a generator of phenomena, rather
than a filter on the mapping of reality’ (UC 42) (cf. 4.10, 14, 18f- 5.27f.
8.21, 23). He ‘described the, nervous system as a closed network of
interacting neurons’ that ‘does not have "inputs’ and
"outputs"‘; it is ‘perturbed by structural changes in the network
itself’, which in turn ‘trigger changes’ in ‘the relative activity’ of
‘neurons’ (i.r.). ‘The structure of the system’, specifies what
structural configurations of the medium’ (the ‘environment’)[26] ‘can
perturb it’ and thus ‘determines a domain’ or ‘space of possible effects
the medium could have’ (UC 42f, i.r.). This interaction between system and
medium is termed ‘structural cooping’ and
provides an alternative to ‘extreme’ ‘behaviourist descriptions’ of
‘stimuli and response’ ‘without reference to the structure of organism’
but only to ‘the patterning of events’ (UC 45f, 48).[27] The term figures
conspicuously in Winograd and Flores's own account of understanding and knowing
(cf. UC 10, 45, 47ff, 61, 72, 104, 119; 10.83).
10.82
Maturana ‘rejected’ ‘information processing as the basis for cognition’
and averred that ‘"living"‘ itself ‘"is a process of
cognition"‘ (UC 46). He ‘sought to explain the origins of all phenomena
of cognition in terms of phylogeny (species history) and ontogeny (individual
history) of living systems’ (UC 44, 46) (cf. 9.12). He defined ‘an autopoetic system’ as, "a network of processes of
production, transformation, and destruction of components"‘ whose
‘"interactions and transformations"‘ ‘"continuously
regenerate"‘ and, "constitute the network"‘. ‘A cognitive
explanation’ ‘deals with the relevance
of action to the maintenance of autopoesis in a phenomenal domain’, i.e., with the ‘relevance of the changing
structure of the system to behaviour that is effective for its survival’ (UC
47). Therefore, ‘"learning is not a process of accumulation of
representations of the environment"‘ but of "'transformation of
behaviour through continuous change in the capacity of the nervous system to
synthesize it"‘ (UC 45).[28]
10.83
When ‘structural coupling’ arises from ‘perturbations generated’ by
‘other organisms’, the resulting, interlocked patterns of behaviour’
‘form a consensual domain’ (UC
48). The ‘behaviours involved are both arbitrary’ ‘because they can have
any form as long as they’ ‘trigger perturbations’, and ‘contextual
because their participation’ Is ‘defend only with respect to the
interactions that constitute the domain’ (UC 48f).'Maturana extended the term
"linguistic" to include any’ ‘behaviour in a consensual domain’.
But even in the ordinary sense, ‘human language is a clear example of a
consensual domain, and the properties of being arbitrary and contextual have’
‘been taken as its defining features’ (cf. 13.27). Thus, ‘language’ gets
redefined as ‘a patterning of "mutual orienting behaviour", not a
collection of mechanisms in a "language user'‘ or a "semantic"
coupling between linguistic behaviour and non-linguistic perturbations
experienced by the organism’. From there, Maturana concluded ‘that language
is connotative and not denotative, and that its function is to orient the
orientee’ within a ‘cognitive domain, and not to point to independent
entities’. So, we were told (10.80), ‘the basic function of language is not
the transmission of information or the description of an independent
universe’, but ‘the creation of a consensual domain of behaviour between
linguistically interacting systems’ (UC 50).
10.84
The ability to ‘talk about a world’ Is reserved for ‘observers':
"'human beings"‘ ‘who can generate distinctions in a consensual
domain’ and ‘"operate"‘ ‘''as if external to (distinct from)
the circumstances"‘ (UC 50) (cf. 5.9). Even then, ‘a statement made by
an observer to another’ ‘is grounded not in an external reality but in the
consensual domain shared by those observers’. ‘Properties of things (in
fact, the recognition of distinct things at all) exist only as operational
distinctions in a domain’ ‘specified by an observer’ (UC 51). ‘We speak
as if there were external things and properties’, but ‘this is an
inescapable result of using language’ and ‘not an ontological claim’.
‘This idea that all cognitive distinctions are generated by an observer’
unites Maturana with ‘gestalt psychology’ (e.g. Kohler 1929) and ‘recent
work in systems theory and cybernetics’ (e.g. von Foerster [ed.] 1974; Pask
1976) (UC 51, 38fn) (cf. 11.4).
10.85 A
second and more surprising witness in the case against rationalism and AI is
Martin Heidegger, lauded ‘as the modern philosopher who has done the most
thorough, penetrating, and radical analyses of everyday experience’, where,
‘radical’ seems to have its etymological meaning: ‘lying at the root of
much of that other philosophers have said’ and ‘of our own orientation’ (UC
9). He concentrated on ‘phenomenology,
the philosophical examination of the foundations of experience and action (LC
9). He rejected ‘the separation of subject and object’ in favour of a
‘more fundamental unity’; for him, ‘existence is interpretation’ and
vice-versa (UC 31). ‘His philosophy is based on a deep awareness of everyday
life’, and ‘the issues’ are ‘difficult because they are concealed by
their "ordinary everydayness", (UC 34). [29] Instead of following
Heidegger's critique of language in Unterwegs
zur Sprache (1959), conceptions are appropriated from Sein und Zeit.[30]
10.86
‘Heidegger's discussion of "thrownness" and "breakdown"‘
is used as evidence that ‘models of rationalistic problem-solving do not
reflect how actions are really determined and that programs based on such models
are unlikely to prove successful’ (UC 12; cf. 10.5, 30, 69, 73). ‘Thrownness’
is ‘the condition of understanding in which our actions find some resonance or
effectiveness in the world’ (UC 33). ‘Imagining you are chairing a
meeting’ is offered as an ‘example’ or ‘metaphor’ (UC 34, 36). There,
‘you cannot avoid acting’ (UC 34).'You cannot step back and reflect on your
actions’. ‘The effects of actions cannot be predicted’, so ‘you cannot
count on rational planning’ to ‘achieve your goals’ (UC 34f). ‘You do
not have a stable representation of the situation’ but at most ‘fragmentary,
possibly contradictory’ ‘pieces’. ‘Every representation is an
interpretation, so ‘even in the post-mortem, your description’ ‘is hardly
an objective analysis’ ‘subject to proof’; ‘there is no ultimate way to
determine that any one Interpretation Is really right or wrong’, and ‘the
people whose behaviour is in question may well not be in touch with ‘their own
deep motivations’.
10.87 For Winograd and
Flores, the ‘study of Heidegger reveals the central role of breakdown in human understanding’ and ‘activity’ (UC 165f).
‘Breakdown’ is the moment when ‘objects and properties’ ‘that
constitute the domain of action for a person’ and are ‘not inherent in the
world’, ‘emerge’ and ‘become present-at-hand’ (UC 36, 166). Such ‘a
breakdown is not a negative situation to be avoided, but a situation of
non-obviousness in which the recognition that something is missing leads to
unconcealing (generating through our declarations) some aspect of the network of
tools’ we are ‘using’ (UC 165).[31] And if ‘the objects and properties
that constitute the domain of action for a person are those that emerge in
breakdown’, then , breakdowns play a fundamental role’ in ‘the analysis of
a human context of activity’ (UC 166). ‘A breakdown reveals the nexus of
relations necessary’ for the ‘task’. When a person is, hammering, the
hammer as such does not exist’ (huh?); ‘it is part of a background of
readiness-to-hand’ ‘taken for granted without explicit recognition or
Identification of the object’ (UC 36). ‘The hammer presents itself only when
there is some kind of breaking down’, e.g. if ‘it breaks or slips from
grasp’ or simply ‘cannot be found’. ‘Observers’ ‘may talk about the
hammer’, ‘but for the person engaged in the thrownness of unhampered
hammering, it does not exist’. The same case is made for a, computer': ‘my
hand and arms, a keyboard, and many complex devices that mediate between it and
a screen -- none of this equipment is present for me except when there is a
breaking down’ (UC 36f). Evidently, something unusual is meant here by
‘exist’ and ‘present’.[32]. Especially it it applies to what ‘cannot
be found’.
10.88 ‘Whenever we treat
a situation as present at hand, analysing it in terms of objects and their
properties, we thereby create a blindness’
(UC 97). ‘Our view is limited to what can be expressed in the terms we
have adopted’. This ‘is necessary and inescapable: reflective thought is
impossible without the kind of abstraction that produces blindness’. At best,
we can become ‘aware of the limitations that are imposed’.
10.89
Armed with these diverse conceptions and arguments from ‘biology,
hermeneutics, and phenomenology’, whose ‘unity [33] lies in the elements of
the tradition they challenge’, Winograd and Flores set out to displace ‘the
rationalistic tradition’ with ‘a new orientation’ relating to ‘the
fundamental questions of what it means to exist as a human being, capable of
thought and language’ (UC xii, 70) (cf. 10.74). ‘Cognition’
is not ‘a distinct function ‘separated from the rest of the activity of
the organism’, like ‘respiration’ (UC 70). Nor can ‘cognition’ be
‘characterized’ or ‘explained’ in terms of a ‘knowing
"subject"‘, or of ‘manta states’, ‘models’, and
‘operations’, or of ‘representations, concepts, and ideas’, or of
‘detached reflection’, ‘gathering information’, ‘manipulating
symbols’, and ‘reasoning’ (UC 71-74). All such accounts are beset by
‘naiveté’ and ‘blindness’. Instead, ‘cognition’ is ‘a pattern of
behaviour relevant to the functioning of the person or organism in the world’
(UC 71) -- a wide definition covering humans as well as ‘babies’,
‘frogs’, and ‘worms’ (UC 52, 36, 38, 46, 49, 103, 105), but not
computers.
10.90
‘Understanding’ is also redefined
so as to place it far beyond the reach of computers. In Winograd's first book,
‘understanding language’ was described as ‘converting from a string of
sounds or letters to an internal representation of meaning’ (UN 23). Now,
‘understanding’ is described as ‘a commitment to carry out a dialog within
the full horizons of speaker and hearer in such a way that new distinctions
emerge’ (UC 124). ‘Any individual, in understanding his or her world, is
continually involved in activities of interpretation’, which ‘depends on the
entire previous experience of the interpreter and on situatedness in a
tradition’, including ‘prejudice or pre-understanding’ (cf. 10.26); and
‘the search for a full formalization of the pre-understanding that underlies
all our thought and action’ is ‘fruitless’ (UC 28, 75, 99). ‘In all
language acts, meaning is relative to what is understood through the
tradition’ that ‘forms the background within which we interpret and act’ (UC
61, 63, 7) (cf. 3.1; 10.80). In ‘conversation’, ‘That is not said is
listened to as much as what is said’ (UC 66) (cf. 12.78).
10.91 In sum, the thrust of the case against AI is that understanding and
the related processes (cognition, thought, knowledge, interpretation, etc.)
entail a rich shared ‘background’; ‘not a set of propositions, but our
basic orientation of "care" for the world’ (UC 75f, 57f- cf. 10.67,
71, 78). Since the background cannot be ‘fully’ or, ‘completely
articulated’ (UC 11, 29, 31, 53, 75, 99, 124, 174), such processes cannot be
captured by programs of any present or future design. ‘Artificial intelligence
is an attempt to build a full account of human cognition into a formal
system’, and ‘the computer’ can only ‘operate’ when ‘the background
is articulated and embodied in its programs (UC 75). ‘But the articulation of
the unspoken is a never-ending process’.
10.92 Winograd and Flores further widen the gap between computation and
understanding with categorical denials: that ‘biological beings’ ‘can
never have knowledge about external reality’, ‘language cannot
be understood as the transmission of information’; ‘our acts’ ‘cannot
be understood as the results of a process’ of planning and reasoning’;
‘the effects of actions cannot be
predicted’; and so on (UC 50 76, 162, 71, 34, i.a.). As assertions, these
statements are hard to square with ordinary experience. Human beings have
knowledge of reality, language has been understood this way, especially in
linguistics and communication science, acts are understood in terms of plans,
and effects are predicted, especially in management science -- ‘naively’ no
doubt from some deeper perspective, but by highly competent people and with
tangible successes. More detailed and developed arguments are required here than
UC provides. Presumably, what is meant is: ‘language cannot be understood only
‘as a means of transmitting information’, ‘the effects of actions are often
‘unpredictable’, and so on. As they stand, the statements seem too rely too
heavily on the ‘introspection’ and ‘speculation’ diagnosed in AI (UC
114, MSF 94). Nor is the fit fully spelled out between the philosophical theses
[34] and the non-speculative evidence, such as the material on the nervous
systems in frogs and the physical constructions of computers (10.70f, 81).[35]
10.93 Presumably, the
fitting recourse would be to follow the book's own argument by turning to ‘the
theory of speech acts -- the analysis of language as meaningful acts by speakers
in situations of shared activity’ (UC 54). We might then situate the book
under some ‘speech act mode’ other than ‘assertive’,
the mode that ‘commits the speaker to the truth of the expressed
propositions’ (UC 58). The scheme of ‘illocutionary points’ offers the
following alternatives: ‘directives
attempt to get the hearer to do something’; ‘commissives
commit the speaker’ ‘to some future course of action’; ‘expressives’ convey ‘a psychological state’; and ‘declarations
[often called performatives] bring
about a correspondence between the content of the speech act and reality’
(e.g. ‘pronouncing a couple married’) (cf. Searle 1975). The book is a bit
‘expressive’, more so than Winograd's earlier ones, but not predominantly
so. To call it ‘declarative’ would be premature. So we are left with
‘directive’ and ‘commissive’. What then do the authors want the reader
to do, and what are they promising?
10.94 In addition to their plea for a new
‘ontology’ and for a more humanly appropriate alternative to the
‘rationalistic tradition’, Winograd and Flores have a product to sell -- not
just a theoretical ‘device’ (like Chomsky had, 7.92), but a software
package. Recognizing the ‘danger’ of blindness brings with it the
‘opportunity’ to, create computer systems whose use leads to better domains
of interpretation’ (UC 179). ‘These systems’ are to arise from
‘ontological designing’ by ‘engaging in a philosophical discourse about
the self -- about what we can do and be’. We can join in ‘a continuing
evolution of how we understand our surroundings and ourselves -- of how we
continue becoming the beings we are’, even ‘in settings far away from
computer devices’. ‘These questions’ have ‘direct relevance’ for
‘our understanding of computers and the possibilities for the design of a new
computer technology’ (UC 70). For instance, ‘computer tools can aid in the
anticipation and correction’ not just of ‘computer breakdowns’, but of
‘breakdowns’ ‘in the application domain’ (UC 166).
10.95 The product, called ‘The Coordinator
System’ and marketed by ‘Action Technologies’ (founded by Flores), is
presented as ‘the first example of a new class of products’ and ‘unique
among software systems already in widespread use by virtue of having been
consciously developed from a language/action perspective’, and its
‘commercial success’ is attested (UC 159; Winograd 1988:85f, LAP 5) (150,000
users by October 1989). Here, ‘an active stance’ is taken ‘in modifying
the activities in the human organization system through the way it is supported
in computer technology’ (1988:86). The system is intended to be ‘effective
in getting work done whenever that work involves communication and coordinated
action among of a group of people’ (LAP 5).
10.96 However, the complex and wide-ranging
philosophical argument is difficult to realize in a concrete product. No one
would seriously propose, for example, that the users be briskly thrown around
the room during office meetings by a large SHRDLU-type robot to illustrate and
remind them of the conception of ‘thrownness’ and to make sure they aren't
‘stepping back (or anywhere else) and reflecting on their actions’; or to
make the system constantly ‘break down’ (e.g. programming it to write like
Heidegger) 'in order to reveal ‘the objects and properties that constitute the
domain of action’ (10.86f). Obviously, a more circumspect implementation is
needed.
10.97 As far as I can gather from published
descriptions, the most clearly theory-based part of the design is the embodiment
of the scheme of ‘illocutionary points’ in a menu for ‘conversations for
action’, which are ‘the central coordinating structure for human
organizations’, and, in the designers’ view, have ‘surprisingly few
basic’ ‘building blocks’ ‘that frequently recur’ (LAP 10, UC 159). The
‘taxonomy of speech acts’ and the ‘diagram of conversation structure’
provided in UC thus can ‘deal with the fundamental ontology of linguistic
acts’ and at the same time ‘provide a basis for the design of tools to
operate in a linguistic domain’ (UC 159).
10.98 In
a ‘conversation for action’, ‘one party makes a request to another; the
request is interpreted by each party as having certain conditions of
satisfaction which characterize a future course of action’ (LAP 7f). The
receiver can ‘accept (and thereby commit to satisfy the conditions), decline
(and thereby end the conversation), or counter-offer with alternative
conditions’ (LAP 8). To ‘perform a speech act’, the user ‘selects an
illocutionary force’ from a menu with ‘request/promise, offer/accept’, and
‘report/acknowledge’, ‘indicates the prepositional content, and explicitly
enters temporal relationships to other (past and anticipated) acts’ (UC 159).
‘By making an explicit declaration of this force, we can avoid confusion and
breakdown due to differences (intended or unintended) in the listening of the
concerned parties’. ‘Relationships’ between ‘speech acts’ are also
made explicit by ‘the need to select among pre-structured alternatives’ at
‘the workstation’ (LC 159f). And ‘the user is coached to explicitly
represent the temporal relations'[36] in ‘the network of commitment’, so as
to allow ‘monitoring’ and ‘warning of potential breakdowns’. ‘If a
certain request (e.g. for payment) has not been met’, ‘other requests are
made’ -- something the ‘system’ can do ‘without direct intervention’ (UC
161).
10.99
Winograd and Flores concede that ‘a mutually visible manifestation’ of,
illocutionary forces’, though ‘valuable’ for ‘everyday communications
within organizations’, is not ‘equally applicable to all situations’ (UC
161f). ‘In many contexts, this kind of explicitness is not called for, and may
even be detrimental’; ‘language cannot be reduced to a representation of
speech acts’ (UC 162). Indeed. If the "'shy young man desperately longing
for love"‘ in one of Weizenbaum's sentimental examples had to spell out
the commitments implied in his request "'will you come to dinner with me
this evening?"‘ (UC 111) and the ‘action’ he hopes to get, he would
never speak to the lady at all. Or, more to the point here, a great deal of
business communication depends on taking care to keep one's interlocutors,
especially consumers, unaware of what promises and commitments are entailed.
10.100
Winograd and Flores themselves do not open their book with a statement of intent
to promote and market a product, but raise the issue toward the end to
illustrate the elaborate philosophy which is the authors’ genuine concern.
Some problems are entailed in seeming to speak (or write) not ‘defectively’,
but ‘assertively’, i.e., in the mode under attack -- of expressing true
propositions about the impracticality of expressing true propositions, of
marshalling information (e.g. about neurobiology) to demonstrate that language
doesn't convey information, and of proving the authors really know reality to be
really unknowable and unprovable.
10.101
If, as UC recommends, we should consider wider contexts and backgrounds, we
might do the same for the act of writing the book. For example, we might
consider what pertinent arguments and materials are not presented. No mention is
made of the keen competition for cognitive science funding that elicits attacks
on AI from the philosophers like Dreyfus and Searle. No explicit appeals are
made to Marxist argument (aside from the reference to Jürgen Habermas), which
demonstrated that ‘meaning is fundamentally social’ and ‘emphasized the
historicity of our ways of thinking’ and ‘understanding’ (cf. UC 33, 7)
with great detail and conviction. No parallels are drawn with Zen teachings or
Taoism, which have expounded the illusory qualities of direct external
experience. And most importantly, the social contexts of computer design and
‘artificial intelligence’ are relentlessly bared, but not the contexts of
philosophy, which gets presented as a disinterested search for ‘the basic
nature of human language and action’ (cf. UC 158; 10.74).[37] Perhaps
‘blindness’ to certain things can be good for business.
10.102
The upshot is: ‘let the people do the interpretation of natural language and
let the program deal with explicit declarations of structure’ (LAP 11). Just
what ‘the Coordinator’ does: ‘all of the interpretations’ ‘are made by
the people who use the system’ (LAP 14). ‘This leaves the users free to
communicate in ordinary language that depends on the background of the
reader’, or for additional convenience, ‘the user can replace the text’
altogether with prefabricated ‘pro forma compositions’ (like "'No, I
counter-offer"‘), which, ‘experience has shown’, work for ‘a
surprising number of messages" (LAP 11). And it leaves the programmers free
to market a system ‘based’ ‘on theories of language without attempting to
program "understanding"‘ (LAP 14). ‘The propositional content of
speech acts’ need not concern the system, especially after ‘propositions’
have been tossed in with the baggage of ‘rationalism’ and its ‘formal
semantics’ and ‘truth conditions’ (UC 161, 19, 57, 89, 117). It seems a
bit ironic, though, when these ‘critics’ fault AI because ‘the success of
computer programs dealing with natural language’ ‘is due to the constrained
nature’ of their ‘domains’ (LC 29), seeing that ‘the Coordinator’ is
itself so constrained.
10.103 Still, when we do look
at the issues in their wider context, the span of Winograd's career begins to
seem consistent. Such broad repudiations of one's own earlier work are
admittedly uncommon, which is why paradigm shifts usually involve generation
shifts (10.34). Even Chomsky, who has endlessly tinkered with the details of his
model, drastically cutting back on ‘transformations’, giving up ‘deep
structure’ and shrivelling into ‘minimalism’
(cf. LC 564f) (cf. 7.77), never frontally denounced the whole enterprise he
helped to launch. But Winograd now abjures ‘the rationalist orientation of his
prior training in science and technology’ (UC 38).[38]
10.104
Winograd's consistency may be on a different plane. He is resolved to
‘understand natural language’, which, throughout his career, he has seen as
the centre of human intelligence (10.32, 43, 75). At first, he viewed the
computer as a key ‘metaphor’, with the ‘data’ being words and sentences
treated as occasions to execute processes: trigger operations, identify input,
run searches, match patterns, fetch or modify data, make or update a record, and
so on. He accepted metaphoric correlations between what computers do and what
people do in UN, but retreated to a neutral stance in LC, and declared his
opposition to the whole idea in UC. He remains convinced that the interaction of
humans and computers must be designed to emphasize the human aspects, but he has
reversed his original belief that the best way for achieving this is to make
computers ‘duplicate the knowledge or thought patterns of people’ or to
‘project human capacities onto the computer’ (LAP 10; UC 137).
10.105
His allegiances shifted accordingly. He started with systemic grammar because
the latter is much closer than most others to what people actually say and do
(9.4, 6). Later, he treated all grammars on fairly equal terms, examining their
formal aspects In terms of computability. Later still, he turned away from
formality itself and looked to philosophy and biology to articulate his
discontent. At each stage, he was radically consistent, drawing all the
consequences of each shift in his outlook, instead of merely tinkering with the
design of the theory while leaving its ontological claims firmly In place, as
Chomsky and his followers have done.
10.106
Only in UC does a ‘revolution’ appear on the agenda of two ‘converted
scientists’ who seem intent on ‘radically throwing away all that came
before’ while providing a ready-made ‘technological application’ as a
‘measure of progress’ (cf. 11.35). The ‘computational or cognitive
paradigm’ and the end of LC's ‘history’ is to be replaced with an
‘actional paradigm’, whose metaphor might ‘language as negotiation’.
Because the paradigm so far is strongly oriented toward technology and business,
it's not clear what new sciences or disciplines (besides biology, philosophy,
hermeneutics, and phenomenology) would become dominant and what problems or
puzzles they would solve. If ‘rationalism’ is indeed overthrown, most major
issues in formal linguistics and semantics (particularly the generative school)
become ‘less relevant’ or even get ‘dropped from consideration’ (cf. LC
7; UC 14, 17f, 33). In addition, UC says (In connection with ‘the fifth
generation’) that the ‘more ambitious AI goals, such as’ ‘real natural
language understanding’ and ‘general-purpose machine translation’ ‘will
be dropped’ (UC 138).
10.107
In fact, it is not clear how any ‘normal’ science could function after a
revolution that challenges the very ‘mainspring of Western science’, denies
that ‘observations’ are ‘grounded in an external reality’, and casts
doubt on the activities of ‘reasoning’, ‘rational planning’, ‘detached
reflection’, and ‘information gathering’ and ‘transmission’. Within
the new outlook, normal science might be viewed as a period of ‘thrownness’,
and a scientific crisis as a ‘breakdown’. But we might argue equally well
that science remains in a continual state of breakdown, namely, ‘a situation
of non-obviousness in which the recognition that something is missing leads to
unconcealing (generating through our declarations) some aspect’ (11.87): if
so, then surely the argument in UC should work for science, not against it.’
Linguistics, and above all semantics, would be breakdowns -in the most trenchant
sense, because they systematically isolate instances of language from their
unhampered communicative settings and thereby transform their obviousness into
recalcitrant problematics (13.47). What further paradigms might arise if this
tactic were systematically reversed is barely foreshadowed in Winograd's latest
argument. But, as he says, we will undoubtedly require a far more concerted and
open-minded effort among all who ‘share the enterprise of creating a new
understanding’ of ‘language as a human phenomenon’ (LC ix).
Notes
[1] See the top of the
Chapter.
[2]
According to Winograd (personal communication), ‘SHRDLU’ is not an anagram.
It is composed of the 7th through 12th most frequent letters of English, which
therefore formed the second row of the keyboard on the old linotype machines;
operators would pad lines by running their finger down the row to leave room for
proofreaders, who did not always notice it. It was also used in a science
fiction story by Frederick Brown about an animated linotype machine, and
Winograd must have read it in high school.
[3]
Winograd contrasts the ‘usual’ ‘binary tree’ of ‘grammar’, which
‘analyses the constituent structure of a sentence’ to show how ‘it is
built up out of smaller parts’, against ‘systemic grammar’ which shows how
‘groupings of phrases’ ‘are used for conveying different parts of the
meaning’ (UN 16f). Compare Halliday's similar demonstration in IF 22ff (9.33).
[4]
Halliday later decided (unwisely, I think, in view of the other uses people have
made of the term) to call this ‘embedding’ instead of ‘rankshift'- and he
doesn't assign, it much importance in his ‘Introduction’, at least not at
the clause level (see 9[24]).
[5]
Also, ‘we can allow unmarked features" when ‘the choice is between
presence or absence’ (UN 20) (but. cf. 5[12]).
[6]
‘An explosion of paths’ occurs when ‘the number of possibilities grows
exponentially’, a danger for example when ‘conjunction’ is included in a
‘grammar’, because ‘conjunctions’ ‘can occur at almost any place in
the structure’ (LC 258f- cf. UN,
71f, 90,
157, LC 53, 92, 185, 347, 371f, 397, 524f). Here too, ‘using criteria based on
meaning’ helps to impose ‘limits’ (LC 259).
[7] In Chomsky's
transformational theorizing, ‘features’
are the minimal, presumably intrinsic building blocks, whether
‘phonological’, ‘syntactic’, or ‘semantic’, while ‘markers’
are ‘the the elementary units of deep structures’ and may contain whole
‘feature matrices’ (cf. 7.63f, 69-73). Having no ‘deep structure’,
Winograd's system in UN does not maintain a clear distinction between the two
(cf. UN 3, 16, 21, 31, 73. 76, 127, 129, 132, 173). In LC the terms are closer
to their Chomskyan meanings, e.g., when a ‘phrase marker contains a set of
unordered features’ (LC 572; cf. LC 140, 210, 239, 285, 292, 389, 571).
[8] No ‘sharp
philosophical distinction’ is drawn between these three (UN 27). 'Properties and relations’ can be ‘dea1t with in identical ways’,
‘properties’ being ‘specia1 types of relations which deal with only one
object’ (UN 24). Also allowed are complex types ‘themselves having
properties and entering into other relations’ (UN 24f). Because ‘most
objects and relationships do not have
simple English names’ or ‘share their names with a range of other
meanings’, the notation for ‘the internal use of the system’ made a
‘unique name’ out of. ‘a descriptive word and an arbitrary number’, and
attached a ‘punctuation mark, "#", to the name of a property or
relation’ (UN 24f). The ‘fact, "Harry slept on the porch after he gave
Alice the jewels’ would become a set of . HARRY: RELl) (#LOCATION: RELl:
PORCH) (#GIVE: HARRY : ALICE: JEWELS : REL2) (#AFTER RELl : REL2)"‘,
‘putting the name last’ (e.g. REL 1) to ‘make indexing and reading the
statements easier’ (UN 25).
[9]
‘A special check for the order of particles’ handles the perennial
syntacticians. dilemma of discontinuous constructions like ‘"to pick it
up"‘ rather than "to pick up it" (UN 168). Compare LC 249 and
Chomsky's ‘"brought him in"‘ versus ‘''brought in him"‘
(SS 75).
[10]
Of course, Winograd is careful to attribute these biases to ‘speakers’ who
eschew ‘a realistic grammar’ in favour of ‘an idealized’ one (LC 249,
481, 245). Still, ha suggests (wrongly, in my view; cf. Beaugrande 1984) that
‘the ‘general advice’ given by such self-proclaimed authorities ‘is
often sound’ (LC 27). Perhaps LC is intended to offend nobody, but it does use
as a sample ‘phrase ‘'the English teacher whom you never liked"‘ (LC
245).
[11] Only a few of the
‘exercises’ at the chapter ends require prior computer programming skills,
such as ‘write a bottom-up’ and then ‘a top-down nondeterministic parser
for an augmented context-free grammar, assuming that nodes have only synthesized
attributes’ (LC 411). Most of the exercises are of a more linguistic bent,
such as ‘write a set of rules for the use of pronouns’, ‘identify every
word in the following paragraph by its traditional word class’, or ‘draw a
surface structure tree for the given sentence’ and than ‘a deep structure
tree’ (LC 33, 69, 268). Some foreshadow the stance of UC, e.g.: imagine ‘a
Martian with a complete dictionary and grammar of English’ but ‘knowing
nothing about earthly ways’. or list ‘potentially undesirable effects of
developing and using computer systems for natural language’ CLC 33f). And some
are frankly whimsical, such as applying ‘structural approaches’ to, or
writing ‘grammars’ for, ‘the time of day’, ‘a motorcycle’ (Robert
Pirsig [1974] is cited), ‘an academic department’, or ‘a detective solving
a murder’ CLC 128f, 353).
[12]
In a later formulation of ‘the standard assumption’, ‘the observable
organization of language’ is said to result from the ‘cognitive structures
of the speakers of the language’ (LC
279).
[13]
See LC 89, 112, 147, 177, 180, 234, 248, 259, 265f, 274, 277, 287, 295f, 299,
313f, 319, 328f, 333, 338, 348f, 374, 378f, 393, 395f, 401, 468, 473, 504, 522f,
526, 573.
[14]
‘Question answering’ has been a particularly ‘central project’ for
‘computational models of language’ CLC 24). In contrast, ‘text
retrieval’ has often not been based on a cognitive processing approach, but on
‘information theory’, which uses ‘statistics and probabilities’ (cf.
7.38). In UC, ‘statistic and probabilistic’ approaches are declared
‘ontologically vacuous’ and ridiculed for ‘attributing meaning to a sort
of "popularity poll"‘ (UC 62) (13.59).
[15]
More technically, ‘a top-down procedure’ ‘looks for rules for the top
level structure’ and then ‘looks for rules’ for its ‘constituents’,
‘proceeding down the structure tree until it reaches words’ (LC 9). A
‘bottom-up procedure’ ‘looks for rules whose right-hand sides match
sequences of adjacent words’ like those in the ‘input’ and sees if they
can be ‘combined’ ‘into larger constituents’, thus, proceeding up the
structure tree’ until it gets a ‘distinguished symbol’ to ‘cover the
entire input’.
[16]
‘Some parsers used in speech understanding systems operate top-down, but look
for islands from which they work in both directions’ (LC 91, 396). ‘Even
working across in a single direction, it is possible to go from right to
left’, though ‘it seems more natural to proceed in the order words would be
heard in spoken language’ and more plausible for ‘psychological models’
CLC 91). Of course, ‘right-to-left’ would be ‘natural’ for ‘a Hebrew
or Arabic parser’.
[17]
The ‘Mitre Transformational Parser’ (Zwicky et al. 1965) deserves a prize
for slowness: it needed ‘36 minutes for an eleven word sentence’ compared to
‘150 milliseconds’ needed by the ‘Sophie’ parser ‘for’ sentences of
8 to 12 words’ (Burton & Brown 1979) (LC 376).
[18]
Winograd also lists ‘prosody’ under ‘syntactic resources’, but earlier
he associates it with ‘intonation and stress patterns’ (LC 275, 5). Firth,
who championed the term ‘prosody’, seems to have regarded it as a
multi-dimensional phenomenon (cf.8.52, 65ff, 68).
[19]
Though mention is made of ‘thematic structure described by Hal1iday’ and of
‘functional sentence perspective of the Prague school’ as means for
indicating ‘the focus and goals of the speaker’ (LC 277, 282f, 287, 505f),
this aspect is not handled by any computer system I know of for natural
language, not even the one of Winograd and Flores, which is devoted to goals
(cf. 10.97f).
[20]
‘Two grammars are weakly equivalent’ if ‘they accept the same sentence but
assign different structures’; and ‘strongly equivalent if they always assign
the same structures’ (LC 112, 198). For instance, ‘transition networks are
formally equivalent in power to context-free grammars’, but ‘categorial
grammars’ are only ‘weakly’ so (LC 196, 115, 377). A favourite tactic in
linguistics and artificial intelligence is to compare a grammar to a ‘Turing
machine’, which has ‘unrestricted’ ‘power’ (UC 53, LC 144), if not
‘universal’ (Chomsky, AT 62). But for that very reason it bears no useful
resemblance to a human language understander.
[21]
The book was announced to be ‘forthcoming’ in ‘March 1982’ (LC ix) but
didn't appear until 1986, because, according to Winograd, the authors kept
rewriting it. At least the delay gave time to get ‘the Coordinator’ fully
operational and distributed, and to allow LC to find an audience before its
projects were declared unattainable. Who wrote what in UC is not easy to say,
aside from the passages that also appear verbatim in papers published under
Winograd's name alone, e.g. in LAP and MSF. The whole book has a generally
Winogradian style, aside from the passages on Maturana and Heidegger.
[22] For tactical motives,
Herbert Simon's programs like BACON that discover mathematical principles (see
Langley, Bradshaw, Simon, & Zytkow 1987) are ignored, while prominent
coverage is given to obvious gimmicks like Weizenbaum's (1966) ‘Eliza’,
which ‘duped’ people (UC 120f, 124) (cf. McCorduck 1979:251-56). We are
assured that the complaints against ELIZA also hold for systems of greater
‘complexity’ and ‘breadth of subject’ (UC 121), a view few AI people
share.
[23]
Only for, computer systems’ does this, corresponding representation
hypothesis’ hold and properly describe ‘how such systems operate’ (UC 74).
[24] In
philosophy, this conception is called ‘verificationism’ (MSF 93) and never
seems to be quite abandoned, despite its impracticality, probably because many
philosophers have no stomach for the complicated empirical collaboration with
cognitive psychology needed to replace it (cf. 13.57).
[25] I
faced problems with exposition here, because Maturana wanted to ‘overcome the
tendency, imposed on us by our language, to treat mental terms’ as
‘descriptions of state or structure’ (UC 47f). So he, introduced a good deal
of new terminology’ or gave his ‘terms’ ‘technical meanings’, because
‘old terminology carries’, a pre-understanding’ and poses a ‘trap of not
saying anything new because language won't permit it’ (UC 40, 44). In their
turn, Winograd and Flores exempt themselves from ‘giving definitions’
because their ‘own theory of language denies the possibility of giving precise
definitions’ (UC 40). They hope ‘the network of meanings will gradually
evolve as the different ideas are developed and the links of their independence
laid out’ (cf. 8.40; 9.29- 13.48).
[26] To
avoid any ‘connotation of a separation’, ‘the term "medium"‘
is used ‘rather than "environment"‘ for ‘the space in which an
organism exists’ (LC 43n).
[27]
‘Neobehaviourists’ ‘postulate an internal state of an organism as well as
a record of Inputs and outputs’ (cf. Suppes 1975) (UC 48). But ‘the focus’
still falls on ‘external stimuli’.
[28] So
‘recall does not depend on the indefinite retention of a structural invariant
that represents an entity (an idea, image, symbol) but on the functional ability
to create"‘ "'a behaviour that satisfies the recurrent
demands"‘ (UC 44) (but cf. 11.42, 50, 59, 71, 89).
[29] ‘Heidegger's writings are
important and difficult’, and ‘hard to relate to reality’, but ‘this is
the opposite of what Heidegger intends’ (UC 27, 33f, 36). Actually, the main
difficulty lies in his self-indulgent, arcane use of the German language, in no
way ‘ordinary’ or ‘everyday’. Sample: ‘Im Nennen sind die genannten
Dinge in ihr Dingen gerufen. Welt und Dinge durchgehen einander. Hierbei
durchmessen die Zwei eine Mitte. In dieser sind sie einig. Also als Einige sind
sie innig. Die Mitte der Zwei ist die Innigkeit. Die Mitte von Zweien nennt
unsere Sprache das Zwischen [...] Die Innigkeit von Welt und Ding west im Schied
des Zwischen’ (Heidegger 1959). (You get all that? I sure don’t.) English
translation increases the obscurity, e.g., when ‘Dasein’ becomes
‘Being-in-the-world’, or when ‘present-at-hand’ is made something quite
different from ‘ready-to-hand’ (UC 36) (cf. 11.87).
[30] UC
follows the ‘discussion’ by Hubert Dreyfus (1990), a philosopher who is also
AI's most implacable foe and the most vociferous and bumbling forecaster of
‘what computers can't do’ (cf. Dreyfus 1972) (UC 32). Though Winograd and
Flores concede ‘a mystical feel’ in Dreyfus’ ‘critique’, they do not
report his more vulnerable claims, e.g. when he averred that a ten-year-old
child could defeat any chess-playing computer and, some time later, was himself
beaten at chess by a computer. On the whole ‘Dreyfus affair’, see McCorduck
(1979:180-205).
[31]
Elsewhere, the term breakdown’ is substituted for ‘problem’ (UC 77),
probably because the usual method of ‘solving a ‘problem’ is reckoned
under the ‘rationalistic orientation': you ‘characterize the situation in
terms of identifiable objects with well-defined properties’, then you ‘find
general rules’ and ‘apply’ them ‘logically’ to ‘draw conclusions
about what should be done’ (UC 15). But for avoiding ‘negative’ overtones,
‘problem’ would be a better term than ‘breakdown’.
[32] As
Winograd and Flores would discover if they tried their argument on carpenters,
for whom tools exist most when working properly and least when they can't be
found. Or, if I, in a Luddite manner, go smashing computers with a hammer, then
the computers come into existence, but the hammer does not until I am hampered
by the police -- a tricky point If I plead innocent because the alleged weapon
didn't even exist at the time of the crime and I was only making the computer
become ‘present-at-hand’, which no law forbids.
[33] In LC, we were alerted
(regarding ‘transformational linguistics’) to the importance of ‘the
history and politics of the field': papers’ may be ‘organized’ with
‘mixed’ ‘arguments’ ‘to attack the complex of beliefs held by some
rival’ (LC 557). In my view, UC owes some of its ‘unity’ to the same goal
(Note 35).
[34]
While the earlier books were sceptical about ‘philosophy’ (UN 25ff, LC 61),
it now becomes a main stone for cracking AI, and Winograd counts himself among
the ‘philosophers of language’ (MSF 101). But how can this work if AI models
are ‘generally equivalent to older philosophical ones’ (Fodor 1930) (UC
109)?
[35] 1
don't fully see how Maturana and Heidegger share a ‘remarkably similar
understanding’ (UC 71). ‘Readiness to hand’ is equated with ‘structural
coupling’ on the grounds that both emphasize ‘unreadiness or breakdown’
and both writers are credited with undercutting the notion of ‘existence’
(LC 72f). But for Maturana, it is the observer, not the breakdown, that grounds
the ‘existence of object and properties’ (LC 73), and surely observation
need not wait for a breakdown.
[36] The
system ‘keeps track of time relations’ because ‘time’ is ‘a critical
aspect of every speech act’, ‘plays a surprisingly large role in producing
effective conversations’ (UC 161, LAP 11). The idea that ‘a promise is not
really a promise unless there is a mutually understood time for satisfaction’
seems to me exaggerated.
[37] The
work of Heidegger, whose style ensured that ordinary people would never
understand his works, and who, as I have said, was heavily involved with the
Nazi regime in Germany (Ott 1983), is treated outside of history, quite apart
from the far-reaching critiques of his work within post-structuralism.
[38]
Just as ‘the foundations of hermeneutics and phenomenology’ at first
seemed’ nearly inaccessible’, ‘readers with a background in the
rationalistic’ or ‘analytic’ tradition’ might be prone to get
‘impatient’ or see ‘"logical holes"‘ in ‘our argument’ (UC
33, 60, 104). As for SHRDLU, LC cited it as a system that ‘covered a wide
range of English phenomena’, and UC as ‘one of the most widely known
programs’ of its ‘kind’ (LC 310; cf. LC 351, 364ff, 375f, 391, 396; UC
109). It reaps mild criticism in LC, mainly technical: the system was ‘tied to
a specific processing order’ and was ‘complex and difficult to modify
because the interaction among rules was implicit’ in that ‘order’ (LC 261,
310). In UC, SHRDLU gets more soundly rapped for its ‘ad hoc style’ of
‘reasoning’, its ‘rationalistic approach to meaning’, its ‘rough
approximation’ in ‘determining referents’, and its ‘permanent structure
of blindness’ (UC 110f, 113, 121).