1. categories (work well)

2. definitional approach (do not work well)

3. comparison approach (compare to existing knowledge)

4. network approach (how is info stored in network?)

1. a cognitive unit of meaning-an abstract idea or mental symbol

2. a "unit of knowledge"

3. built from other units which act as a concept's characteristics

4. usually associated w/ symbol or language

1. help to understand indivual cases not previously encountered

2. pointers to knowledge

-categories provide a wealth of general info about item

(ex: what you know about psychology)

-allow us to identify special characteritics of specific item

1. knowing something about a category (ex: cats) provides a great deal of into about item

ex: has wiskers, is furry, has 9 lives, purrs and meows

-we apply/access this knowledge when seeing new cat w/out having to relearn the concepts

1. determine category membership based on whether the object meets the definition of the category

ex: defining features of a cat "furry, has wiskers..." or a square "plane figure w/ 4 right angles"

-can't explain "natural" objects (ex: birds-can vary greatly such as a robin vs. a flamingo)

-not ALL members of same category have same features

ex: all birds do not fly (ostrich)