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MODELS OF HEURISTIC PROCEDURE MODIFICATION

Posted on:1982-12-23Degree:Ph.DType:Thesis
University:Carnegie Mellon UniversityCandidate:NECHES, ROBERT TOBIASFull Text:PDF
GTID:2476390017965012Subject:Psychology
Abstract/Summary:
The thesis examines utilization of meta-knowledge in developing improved procedures. Protocol studies of a symbol-manipulation task and a computer graphics editing task reveal a process of procedural refinement beyond mere automatization. Procedure modifications stem from fast processes which make small resource demands and produce changes of a local nature. These processes may involve "pre-compiled" heuristics for determining when and where to apply transformations (procedures for particular kinds of changes).; Twenty-one heuristics for evoking transformation types are discussed, along with a range of situations in which they could apply. The analysis of heuristics is applied in a formal analysis of children's addition procedures. Many young children add by a counting procedure called the SUM, or "counting-all", method. A few years later, the most prevalent strategy appears to be the MIN, or "counting-on", method. The formal analysis which starts with the SUM procedure, shows that the heuristics could find patterns in addition procedures that would produce a developmental sequence of procedures leading from SUM to MIN. This development is modelled as an additive production system, in which the MIN procedure is obtained from the SUM procedure by the insertion of a series of productions that mask or circumvent pre-existing productions. Procedures obtained by adding a subset of these productions represent viable intermediate strategies along the path from SUM to MIN. Evidence is presented for the psychological reality of strategies predicted by the formal analysis.; A production system architecture, HPM, is developed for exploring models of heuristic procedure modification. Given an initial production system for the SUM method coded in its formalism, HPM can discover for itself some of the productions in the additive set. HPM is designed around a goal-structured formalism that simplifies its learning task by providing a domain-independent representation for specifying the heuristics, and by imposing constraints that reduce the amount of reasoning required to construct a correct modification. However, the presence of information required for learning severely stresses HPM's attention focusing mechanisms. Context-sensitive methods for associative retrieval and conflict resolution reduce this stress.
Keywords/Search Tags:Procedure, MIN, SUM, HPM
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