[sci.lang] Categorization: Lakoff's mistake.

markh@csd4.milw.wisc.edu (Mark William Hopkins) (12/21/88)

In article <719@quintus.UUCP> ok@quintus.UUCP (Richard A. O'Keefe) writes:
>To continue this rather constructive approach of suggesting good books
>to read that bear on the subject, may I recommend
>
>	Women, Fire, and Dangerous Things
>	-- what categories reveal about the mind
>	George Lakoff, 1987
>	U of Chicago Press, ISBN 0-226-46803-8
>
>I don't think the data he presents are quite as much of a challenge to
>the traditional view of what a category is as he thinks, provided you
>think of the traditional view as an attempt to characterise ``valid''
>categories rather than actual cognition, just as classical logic is
>an attempt to characterise valid arguments rather than what people
>actually do.  As an account of what people do, it is of very great
>interest for both AI camps, and

I don't think it is even a challenge to the traditional view, when the view
is taken as an attempt to characterize human cognition.

Lakoff's essential argument is that humans do not form categories whose
membership is based on necessary and sufficient conditions (the Classical view 
of Categorization).  As a basic fill-in-the-blank example consider a category,
whose members have a majority of the properties out of the three: A, B, C. 
Lakoff asserts that this kind of category defies the Classical view, because a
given member need not have ANY of the three properties, nor have them ALL 
though it would have most of them.  None of the criteria is necessary and
none sufficient.

Yet this kind of argument does not rule out the Classical view, because the
predicate:
		    (A and B) or (B and C) or (C and A)

*IS* a necessary and sufficient condition for membership to such a class.
Forgetting about that magical word "or" is Lakoff's mistake.  Or could it
be that the people who hold to the Classical view have also made the same
mistake of forgetting about that word?

As a more concrete example, Lakoff brings up the Motherhood Test problem.
The idea is that there as MANY criteria that determine whether a given
woman is your mother or not, none of which need be possessed by any given
mother:  she could have given you birth to you, she could have nurtured you,
he/she could be female, etc.  But it's really the same kind of class as that
mentioned above.

zhang@cogsci.ucsd.EDU (Jiajie Zhang) (12/22/88)

In article <18@csd4.milw.wisc.edu>, markh@csd4.milw.wisc.edu (Mark William Hopkins) writes:

> I don't think it is even a challenge to the traditional view, when the view
> is taken as an attempt to characterize human cognition.

Well, I have to disagree with your claim.  On the contrary, I think it
is a challenge to the traditional view, especially when human
cognition is concerned.  
  
> Lakoff's essential argument is that humans do not form categories whose
> membership is based on necessary and sufficient conditions (the Classical 
> view of Categorization).  As a basic fill-in-the-blank example consider a 
> category, whose members have a majority of the properties out of the three: 
> A, B, C.  Lakoff asserts that this kind of category defies the Classical 
> view, because a given member need not have ANY of the three properties, nor 
> have them ALL though it would have most of them.  None of the criteria is 
> necessary and none sufficient.
> 
> Yet this kind of argument does not rule out the Classical view, because the
> predicate:
> 		    (A and B) or (B and C) or (C and A)
> 
> *IS* a necessary and sufficient condition for membership to such a class.
> Forgetting about that magical word "or" is Lakoff's mistake.  Or could it
> be that the people who hold to the Classical view have also made the same
> mistake of forgetting about that word?

By assuming that: (1) classical view of categorization is the view
that the membership of a category is based on necessary and sufficient
conditions, (2) Lakoff thought that classical view was just the one you
mentioned (actually he didn't), and (3) the ABC example you gave which
you think Lakoff used to defy the classical view can be stated in a
predicate which is a necessary and sufficient condition for the ABC
class, you made the following claim: classical categorization theory
CAN account for the phenomena which were considered as counter-examples for
classical view by Lakoff and that Lakoff made a mistake by ignoring the
magical word "or".

Before I make comments, I think it is important to clarify what the
classical view of categorization really is.

There are three basic assumptions of the classical view:

(1) summary representations: the representation of a concept is a
    summary description of an entire class, rather than a set of
    descriptions of various subsets or exemplars of the class.
(2) Necessary and sufficient features: the features that represent a
    concept are (a) singly necessary and (b) jointly sufficient to define
    that concept.
(3) Nesting of features in subset relations: if concept X is a subset
    of concept Y, the defining features of Y are nested in those of X.

(For an extensive review and discussion about different views of
categorization, see Medin & Smith's book Categories_and_Concepts.)

Here comes my comments on your critique on Lakoff.

(1) You assumed that the SECOND assumption of classical view is the one and
only one assumption of classical view.  This is a misunderstanding of
classical view.

(2) You even misunderstood the SECOND assumption of classical view.
Yes, the predicate (A and B)or(B and C)or(C and A) is a necessary and
sufficient CONDITION of the ABC class you gave, but it is NOT a
necessary and sufficient FEATURE of that class.  You confused
CONDITION with FEATURE.  Thus the predicate you gave is not relevant to the
problem of categorization. 

(3) In fact, the example you gave is a disjunctive concept and its
existence is a powerful argument used by people against classical
view, because the second assumption of classical view excludes any
disjunctive concept in classical categories.  Disjunctive concepts can
be accounted for by some alternative views of categorization such as
probabilistic (or prototypic) view and examplar view, but these
two views are also under criticism (Medin & Smith gave a good
discussion about this).

(4) As to the book, I think Women, Fire, and Dangerous Things is a
profound one.  Lakoff's critique on traditional view of language
(Chomskian) is especially worth mentioning (other arguments on 
cognition in general are also interesting).  His critique goes as follows
(hope it is not a misuderstanding):

    (a) Formal-system view of language assumes that (i) language is
        independent of the rest of cognition, that is, language is a separate
        modular system independent of the rest of cognition, and (ii)
        categories are classical (that is, can be characterized by distinctive
        features so that formal operations can be possible).

    (b) Lakoff argued that (i) language makes use of our general cognitive
        apparatus, that is, language is not a modular system, and (ii)
        classical view of categorization can't account for a large amount of
        empirical data and thus is not adequate to serve as a fundamental
        assumption for a general theory of language.

     (c) Combine (a) and (b), Lakoff argued that traditional (or
         formal-system) view of language is wrong.

rwojcik@bcsaic.UUCP (Rick Wojcik) (12/23/88)

In article <18@csd4.milw.wisc.edu> markh@csd4.milw.wisc.edu (Mark William Hopkins) writes:
[On Lakoff's _Women, Fire, and Dangerous Things]

>Lakoff's essential argument is that humans do not form categories whose
>membership is based on necessary and sufficient conditions(the Classical view 
>of Categorization).  As a basic fill-in-the-blank example consider a category,
>whose members have a majority of the properties out of the three: A, B, C. 
>Lakoff asserts that this kind of category defies the Classical view, because a
>given member need not have ANY of the three properties, nor have them ALL 
>though it would have most of them.  None of the criteria is necessary and
>none sufficient.

It's hard to summarize Lakoff's ideas in just a few words.  One should look at
his extensive discussions of examples before formulating an opinion on his
criticism of classical category theory.  Note that his thinking is strongly
influenced by Rosch's psychological theory of prototypes.  Classical
categorization does not explain prototype effects--the impression that some
entities belong more strongly to a category than other entities do.

>Yet this kind of argument does not rule out the Classical view, because the
>predicate:
>		    (A and B) or (B and C) or (C and A)
>
>*IS* a necessary and sufficient condition for membership to such a class.
>Forgetting about that magical word "or" is Lakoff's mistake.  Or could it
>be that the people who hold to the Classical view have also made the same
>mistake of forgetting about that word?

You seem to be saying that, given three possible properties, an entity is
classifiable as a member of the category if it has at least two out of three
properties.  Note that this is hardly the 'classical view', which you seem to
be realizing in your afterthought.  Anyway, to be consistent with what you
said about Lakoff's views above, you would have to chain some more OR's on: or
A or B or C or (A and B and C) or nil.  Then you need some metric for
calculating prototype effects off of such formulas.  In constructing your
metric, take care to reread the chapter on radially structured categories,
where it is noted that some properties are more central than others to a
category.  Work that concept into your metric, and good luck as you drift
further away from the 'classical view' of categories.  :-)

>As a more concrete example, Lakoff brings up the Motherhood Test problem.
>The idea is that there as MANY criteria that determine whether a given
>woman is your mother or not, none of which need be possessed by any given
>mother:  she could have given you birth to you, she could have nurtured you,
>he/she could be female, etc.  But it's really the same kind of class as that
>mentioned above.

Not really.  Womanhood is more central to the category than the properties of
nurturing or doing housework.  On the other hand, it is now thought
biologically possible to grow babies in males.  Would such a male parent be
considered the 'mother'?  Put that in your classical pipe and smoke it.
-- 
Rick Wojcik   csnet:  rwojcik@atc.boeing.com	   
              uucp:   uw-beaver!ssc-vax!bcsaic!rwojcik 

bondc@iuvax.cs.indiana.edu (Clay M Bond) (12/25/88)

A classroom anecdote, inspired by the recent discussion of prototypes:

My students, all being quite as brainwashed as anyone else by our
educational system, were quite fond of the idea that everything could
be packaged up in nice, discrete little units and manipulated mathe-
matically.  They liked the idea that everything was rule-governed, and
when we started talking about cognition, I asked for a show of hands
for the "Classical" theory of categorization.

The vote "for" was unanimous, so I asked them to give me:

	a.  The properties that all members of the category
		GLASS share;

	b.  The properties that all members of the category
		CUP share;

	c.  The properties which differentiate CUP from GLASS
		(courtesy of Labov.)

They all seemed to think this was a brain-damaged idea, as simple as
it seemed to them, and as they gave me properties, I wrote them on the
board under their appropriate category labels.

By the time five properties had been listed they were arguing about
them and giving not only counter-examples, but alternative properties.
By the time another four properties had been listed, we had to put up
yet another category, MUG.  And the argument could have lasted for
days.

They began the discussion thinking not only that the "Classical" system
was correct, but also by logical extension, the more defining properties
they gave, the more discrete and well-defined the categories would be.
They left the classroom realizing that the categories were anything but
discrete, and that the more properties they listed, the less discrete
the categories became.

Something else to put into the Classical pipe and smoke.

-- 
<< **********************DO***WHAT***THOU***WILT********************** >>
<< Clay Bond Indiana University Department of Leather, uh, Linguistics >>
<< bondc@iuvax.cs.indiana.edu          AKA: Le Nouveau Marquis de Sade >>
<< {pur-ee,rutgers,pyramid,ames}!iuvax!bondc ************************* >>

lee@uhccux.uhcc.hawaii.edu (Greg Lee) (12/30/88)

From article <671@cogsci.ucsd.EDU>, by zhang@cogsci.ucsd.EDU (Jiajie Zhang):
"[paraphrasing G. Lakoff] 
"     (a) Formal-system view of language assumes that (i) language is
"         independent of the rest of cognition, that is, language is a separate
"         modular system independent of the rest of cognition, and (ii)
"         categories are classical (that is, can be characterized by distinctive
"         features so that formal operations can be possible).

Isn't this a straw man (or men)?  What do formal systems have to do with
modules?  Take, for instance, Montague grammar.  Where is there any
assumption made about language being a module separate from the rest of
cognition?  (Answer: nowhere.)  Where are categories assumed to be
classical?  (Nowhere.)  What do distinctive features have to do with the
possibility of formal operations?  (Nothing.)

This stuff is just an unwarranted slander against formalism.

Even a modularist would not take language to be *independent* of the
rest of cognition -- rather a system with some *principles* that are
independent.

		Greg, lee@uhccux.uhcc.hawaii.edu

zhang@cogsci.ucsd.EDU (Jiajie Zhang) (01/02/89)

In article <2897@uhccux.uhcc.hawaii.edu>, lee@uhccux.uhcc.hawaii.edu (Greg Lee) writes:

> Isn't this a straw man (or men)?  What do formal systems have to do with
> modules?  Take, for instance, Montague grammar.  Where is there any
> assumption made about language being a module separate from the rest of
> cognition?  (Answer: nowhere.)  Where are categories assumed to be
> classical?  (Nowhere.)  What do distinctive features have to do with the
> possibility of formal operations?  (Nothing.)

Sounds like a religious proof?  Nowhere + Nowhere + Nothing = nothing

Formal system (in the sense of Hilbert's formalism) has been well
justified in mathematics, but there is no a priori warrant that the
underlying principle of natural language in particular and human
cognition in general is just such a formal system.  In the study of
natural language and human cognition, using formal system as
methodology is one issue, treating it as truth is another.

In generative linguistics, there are two important assumptions: (1)
syntax of language is independent of other aspects of language (such
as semantics and pragmatics) and (2) language is independent of other
mental organs.  Obviously, these are modularity assumptions.  There is
nothing wrong if these assumptions are only used for methodology
purpose, but they are fundamentally flawed if they are taken as truth.

Formal system approach to semantics (including Montague grammar) shows
same formal elegance as what we can find in Chomsky's syntactic
discussions, but it fails to account for many empirical data, too.
Model-theoretic semantics, one branch of formal system approach to
semantics, is even logically inconsistent (see Putnam's proof).

The core of classical theory of categorization is set-theoretical
model, which consists of nothing but abstract entities and sets, and
sets of sets, and sets of sets of sets, etc.  Linguists (especially
those in generative linguistics) simply take for granted the classical
theory of categorization.  This is true of every aspect of generative
linguistics.  In generative phonology, distinctive features are those
such as +voiced and -aspirated; sets are those such as segments marked
+F.  In generative syntax, a language is defined as a set of sentences
which are sequences of phonological feature matrices, and a grammar as
a set of rules which characterizes the set of sentences.  Generative
semantics is almost entirely based on classical theory of
categorization, which is set-theoretical.  Classical theory of
categorization is clearly a basic assumption for formal system
approach (at least generative linguistics) to language.  Without
features, sets, sets of sets, etc., formal system doesn't exist, let
alone formal operation.

> This stuff is just an unwarranted slander against formalism.

I don't think any system built on formalism can make sense of this sentence:-)

> Even a modularist would not take language to be *independent* of the
> rest of cognition -- rather a system with some *principles* that are
> independent.

"Independent" doesn't mean "Isolated".  Take generative linguistics as
an example: syntax is viewed as a module independent of semantics, but
syntax is not isolated from semantics.  Actually, semantics is a
another independent module which takes syntax as input.

lee@uhccux.uhcc.hawaii.edu (Greg Lee) (01/02/89)

From article <674@cogsci.ucsd.EDU>, by zhang@cogsci.ucsd.EDU (Jiajie Zhang):
" ...
" The core of classical theory of categorization is set-theoretical
" model, which consists of nothing but abstract entities and sets, and
" sets of sets, and sets of sets of sets, etc.

Most any sort of formal system can be constructed on a set theoretical
foundation.  Any functional relation can be represented as a set.
So?  Is everything that can be represented as a set a "classical
category"?  Hardly.

" Linguists (especially
" those in generative linguistics) simply take for granted the classical
" theory of categorization.

If this were so, it should be possible to examine a generative theory
and point to where the assumption(s) of classical categories are introduced.
I suggested that for the case of Montague grammar, one could not find
such assumptions.  You don't seem to have found any yet.  Repeating the
thesis won't pass for proof.

" This is true of every aspect of generative
" linguistics.  In generative phonology, distinctive features are those
" such as +voiced and -aspirated; sets are those such as segments marked
" +F.

Yes, sets everywhere we look.  But classical categories?  In generative
phonology pronunciations are categorized by their underlying
representations.  Since an arbitrary number of arbitrary transformations
express the relation between underlying and surface, there is no
classical categorization.  (One could contrast this with Daniel
Jones' theory of the relation between phonemes and allophones, which
does appear to be a classical categorization.)

		Greg, lee@uhccux.uhcc.hawaii.edu

lee@uhccux.uhcc.hawaii.edu (Greg Lee) (01/05/89)

From article <2915@uhccux.uhcc.hawaii.edu>, by lee@uhccux.uhcc.hawaii.edu (Greg Lee):

My attempt to defend formal systems from Jiajie Zhang's onslaught was
not intended to be critical of George Lakoff's book, Women, Fire &
Dangerous Things.  I should have made it clear that I was commenting
only on what Zhang wrote.

		Greg, lee@uhccux.uhcc.hawaii.edu

zhang@cogsci.ucsd.EDU (Jiajie Zhang) (01/06/89)

In article <2897@uhccux.uhcc.hawaii.edu>, lee@uhccux.uhcc.hawaii.edu (Greg Lee) writes:
} From article <671@cogsci.ucsd.EDU}, by zhang@cogsci.ucsd.EDU (Jiajie Zhang):
} "[paraphrasing G. Lakoff] 
} "  (a) Formal-system view of language assumes that (i) language is
} "      independent of the rest of cognition, that is, language is a separate
} "      modular system independent of the rest of cognition, and (ii)
} "      categories are classical (that is, can be characterized by distinctive
} "      features so that formal operations can be possible).
} 
} Isn't this a straw man (or men)?  What do formal systems have to do with
} modules?  Take, for instance, Montague grammar.  Where is there any
} assumption made about language being a module separate from the rest of
} cognition?  (Answer: nowhere.)  Where are categories assumed to be
} classical?  (Nowhere.)  What do distinctive features have to do with the
} possibility of formal operations?  (Nothing.)
} 
} This stuff is just an unwarranted slander against formalism.
...

However, 

In article <2935@uhccux.uhcc.hawaii.edu}, lee@uhccux.uhcc.hawaii.edu (Greg Lee) writes:
} 
} My attempt to defend formal systems from Jiajie Zhang's onslaught was
} not intended to be critical of George Lakoff's book, Women, Fire &
} Dangerous Things.  I should have made it clear that I was commenting
} only on what Zhang wrote.

In the first article, Greg Lee acknowledged that what I wrote was just
a paraphrase of one of the arguments George Lakoff made in his book.
In the second article, however, Greg Lee denied what he acknowledged
in the first article.  

This would be a perfect example of nonmonotonic reasoning if Greg Lee
could show us the evidence which made his belief system changed and
how this system changed.  This kind of evidence or justification is
important for the kind of nonmonotonic system like TMS, which may or
may not be enjoyed by proponents of pure formalism, depending on how
formalism is defined.

lee@uhccux.uhcc.hawaii.edu (Greg Lee) (01/07/89)

From article <681@cogsci.ucsd.EDU>, by zhang@cogsci.ucsd.EDU (Jiajie Zhang):
" ...
" In the first article, Greg Lee acknowledged that what I wrote was just
" a paraphrase of one of the arguments George Lakoff made in his book.

It may be an accurate paraphrase -- I don't know, since I haven't
read Lakoff's book.  If what you wrote is an accurate paraphrase,
then my criticisms of what you said could be taken to be criticisms
of what Lakoff said.  If it's not, then they couldn't.
 
" This would be a perfect example of nonmonotonic reasoning if Greg Lee
" could show us the evidence which made his belief system changed and
" how this system changed.

My belief system didn't change.  George sent me a note saying I ought
not to slander a book that I obviously had not read.  Hence my
disclaimer.

" This kind of evidence or justification is
" important for the kind of nonmonotonic system like TMS, which may or
" may not be enjoyed by proponents of pure formalism, depending on how
" formalism is defined.

This is neat.  The discussion we have been having comes to serve as an
example to further the inquiry.  It's a pity that less is going on than
you thought.  I guess I'm still safely monotonic, whatever that means.
An analogy between 'greater-than' and 'implies'?

		Greg, lee@uhccux.uhcc.hawaii.edu