Proceedings of the Annual Meeting of the Cognitive Science Society

The most important support process a case-based reasoner needs is a memory for cases. Among its functions, the memory for cases must be able to select out the most appropriate cases for the case-based reasoner to use at any time. In this paper, we present the selection processes implemented in PARADYME , a case memory designed to work alongside a case-based reasoner.PARADYME has a two-step retrieval process. In the first step, it retrieves the set of partial matches from the memory. In the second, it selects out a small set of "best" matches. PARADYME chooses"best" cases using a set of six preference heuristics: goal-directed preference, salience,specificity, frequency, recency, and ease of adaptation. PARADYME is novel in two ways. Its use of preferences for choosing a best case means that its principles act as selectors rather than restrictors. And its emphasis in choosing best cases is on usefulness rather than similarity.