Introduction; J.L. Kolodner. Indexing, Elaboration and Refinement: Incremental Learning of Explanatory Cases; A. Ram. Derivational Analogy in PRODIGY: Automated Case Acquisition, Storage and Utilization; M.M. Veloso, J.G. Carbonell. Opportunism and Learning; K. Hammond, T. Converse, M. Marks, C.M. Seifert. Integrating Feature Extraction and Memory Search; C. Owens. Wastewater Treatment Systems from Case-Based Reasoning; S. Krovvidy, W.G. Wee. Subject Index.