Learning Prototype-Selection Rules for Case-Based Iterative Design Mark Schwabacher Haym Hirsh Thomas Ellman Department of Computer Science Rutgers University New Brunswick, NJ 08903 CAP-TR-17 The first step for most case-based design systems is to select an initial prototype from a database of previous designs. The retrieved prototype is then modified to tailor it to the given goals. For any particular design goal the selection of a starting point for the design process can have a dramatic effect both on the quality of the eventual design and on the overall design time. We present a technique for automatically constructing effective prototype-selection rules. Our technique applies a standard inductive-learning algorithm, C4.5, to a set of training data describing which particular prototype would have been the best choice for each goal encountered in a previous design session. We have tested our technique in the domain of racing-yacht-hull design, comparing our inductively learned selection rules to several competing prototype-selection methods. Our results show that the inductive prototype-selection method leads to better final designs when the design process is guided by a noisy evaluation function, and that the inductively learned rules will often be more efficient than competing methods. Appears in the Proceedings of the Tenth Conference on Artificial Intelligence for Applications, San Antonio, Texas, March, 1994