Different studies have shown that overextension errors occur in comprehension as well
as in production (Thompson and Chapman, 1977; Kuczaj, 1983; Mervis and Canada,
1983; Kuczaj, 1986). This may suggests that overextension errors may reflect the
denotation of words for children and have implications about how the denotation of object
words may be represented in their minds.
2.2.3 Representation of word’s meaning in the mental lexicon
An adequate theory of how children Ieam the meanings of words such as cats and taking
requires some account of what it is to possess the corresponding concepts of CATS and
TAKING. In accordance with Messer (1994) the term concept will be used to refer to the
representation of a group of entities which are considered to be similar. For example, we
have certain ideas about the characteristics that are necessary to identify the category
“bird” such as flying, having wings, having a certain anatomical structure, etc. However,
the concept of BIRD can be considered to include additional information that is not
necessary to identify birds. For example, the way they fly in different circumstances,
where they build their nests etc. Thus, a concept contains idiosyncratic and general
knowledge about an entity, whereas a category simply contains the information necessary
to identify an entity as being a member of a class.
The process of forming concepts is very complex. How does a child manage to
understand that dogs, which share many characteristics with cats, are indeed a different
group of animals ? Various theories which attempted to offer a description of the category
structure and the formation of concepts are discussed in the following sections.
2.2.3.1 Category structure
2.2.3.1.1. The Classical View Theory
The classical view theory of concepts assumes that mental representations of categories
consist of a summary list of features that individually are necessary for category
membership and collectively are sufficient to determine category membership (Lakoff,
1987; Armstrong, Gleitman and Gleitman 1983). For example, the category "triangle"
meets these criteria. All triangles are closed geometric forms with three sides and interior
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