Memory, thinking and language.pdf

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Evaluation of conceptual models
Within psychology, hierarchical networks, list of defining and
typical features and prototypes have been thought of as rival
models of how concepts are stored in human memory. However,
it seems likely that our minds are much more untidy than any of
these models, allowing us sometimes to exploit the cognitive
economy of hierarchies of biological categories; sometimes to
identify the defining attributes of mathematical and scientific
concepts; sometimes to trade on similarities between features;
other times to use everyday knowledge about typical dogs
and what tables are used for. As Roth (1986) pointed out, the very
same object can be classified differently, depending on the
circumstances, a dog as my pet Fido or as a member of the canine
species.
However, a word of warning. Despite the optimistic tone of the
last paragraph, there are several so far quite unresolved issues. It
simply begs the question to say that humans are capable of
multiple categorizations of objects, as and when required. Is a
standard lamp infinitely classifiable as an untypical example of
furniture, a piece of electrical equipment, a fire risk, a weapon, a
work of art, and so on It is ironic, perhaps, that one of the most
common tests of creativity is to ask people to list as many uses as
they can think of for objects like bricks and standard lamps.
Another dilemma for all category-based models is that
identification of an object as a dog or a cup seems to rely on
knowledge of general categories; yet each object we encounter is
an individual example. It is not often, after all, that we have to
verify in the abstract whether All elephants are mammals or A
sharkis a bird, or are asked to list the attributes of all tables, or all
apples. What people need to know is the best way of dealing with
individual elephants, whether they are encountered in a zoo, or
charging around on a safari. It is difficult enough to decide
whether all poodles are dogs. But what about the even more
idiosyncratic features of individual objects, like my pet dog Fido,
who is yellow, has no tail, and can sing
In the course of daily life, one may come across a one-legged
chair; most standard lamps also have one leg. Yet it is really
unlikely that people confuse chairs and lamps. More important
than the perceptual features, so popular with psychologists, are
the functions of objects. Tables are for eating off and writing on,