[Index] [Next] [Previous]

1.1 A Chunk in ACT-R

In ACT-R, elements of declarative knowledge are called chunks or WMEs (for working memory elements). WMEs are intended to represent chunks of knowledge that a person might be expected to have when they solve a problem. The basic elements of the representation are types and slots. Although types and slots can mean anything, one way to understand them is to think of types as categories (e.g., birds) and slots as category attributes (e.g., color or size). Below are chunks that encode the facts that the dog chased the cat and that 4+3=7: The type of the first chunk is chase and its slots are agent and object. The type of the second chunk is addition-fact and its slots are addend1, addend2, and sum