Chunking in Soar

Abstract

Chunking was previously defined (Rosenbloom & Newell, 1983) as a process that acquires chunks that generate the results of a goal, given the goal and its parameters. The parameters of a goal were defined to be those aspects of the system existing prior to the goal’s creation that were examined during the processing of the goal. Each chunk was represented as a set of three productions, one that encoded the parameters of a goal, one that connected this encoding in the presence of the goal to (chunked) results, and a third production that decoded the results. These chunks were learned bottom-up in the goal hierarchy; only terminal goals — goals for which there were no subgoals that had not already been chunked — were chunked. These chunks improved task performance by substituting efficient productions for complex goal processing. This mechanism was shown to work for a set of simple perceptual-motor skills based on fixed goal hierarchies (Rosenbloom, 1983).