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Maintaining retrieval knowledge in a case-based reasoning system.

Craw, Susan; Jarmulak, Jacek; Rowe, Ray


Jacek Jarmulak

Ray Rowe


The knowledge stored in a case base is central to the problem solving of a case-based reasoning (CBR) system. Therefore, case-base maintenance is a key component of maintaining a CBR system. However, other knowledge sources, such as indexing and similarity knowledge for improved case retrieval, also play an important role in CBR problem solving. For many CBR applications, the refinement of this retrieval knowledge is a necessary component of CBR maintenance. This article focuses on optimization of the parameters and feature selections/weights for the indexing and nearest-neighbor algorithms used by CBR retrieval. Optimization is applied after case-base maintenance and refines the CBR retrieval to reflect changes that have occurred to cases in the case base. The optimization process is generic and automatic, using knowledge contained in the cases. In this article we demonstrate its effectiveness on a real tablet formulation application in two maintenance scenarios. One scenario, a growing case base, is provided by two snapshots of a formulation database. A change in the company's formulation policy results in a second, more fundamental requirement for CBR maintenance. We show that after case-base maintenance, the CBR system did indeed benefit from also refining the retrieval knowledge. We believe that existing CBR shells would benefit from including an option to automatically optimize the retrieval process.


CRAW, S., JARMULAK, J. and ROWE, R. 2001. Maintaining retrieval knowledge in a case-based reasoning system. Computational intelligence [online], 17(2), pages 346-363. Available from:

Journal Article Type Article
Acceptance Date May 31, 2001
Online Publication Date May 31, 2001
Publication Date May 31, 2001
Deposit Date May 31, 2007
Publicly Available Date May 31, 2007
Journal Computational intelligence
Print ISSN 0824-7935
Electronic ISSN 1467-8640
Publisher Wiley Open Access
Peer Reviewed Peer Reviewed
Volume 17
Issue 2
Pages 346-363
Keywords Case based reasoning; Maintenance; Retrieval optimisation; Indexing knowledge; Similarity knowledge
Public URL


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