From: AAAI-92 Proceedings. Copyright ©1992, AAAI (www.aaai.org). All rights reserved. Organization of the American Association for Artificial Intelligence 1992 National Conference on Artificial Intelligence (AAAI–92) Conference Chair William Swartout, USC–ISI Program Cochairs Paul Rosenbloom, University of Southern California Peter Szolovits, Massachusetts Institute of Technology Associate Chairs Matthew Ginsberg, Stanford University Craig Knoblock, University of Southern California Yeona Jang, Massachusetts Institute of Technology Invited Speaker Chair Wendy Lehnert, University of Massachusetts Robot Exhibition and Competition Chair Thomas Dean, Brown University Art Exhibition Chair Joseph Bates, Carnegie Mellon University Program Committee Kevin Ashley, University of Pittsburgh Piero P. Bonissone, GE CRD Wray Buntine, NASA Ames Research Center Tom Bylander, Ohio State University William Clancey, Institute for Research on Learning Gregg Collins, ILS, Northwestern University Greg Cooper, University of Pittsburgh James Crawford, AT&T Bell Laboratories Rina Dechter, University of California, Irvine Jon Doyle, Massachusetts Institute of Technology Ed Durfee, University of Michigan David Etherington, AT&T Bell Laboratories Oren Etzioni, University of Washington Peter Friedland, NASA Ames Research Center Hector Geffner, IBM T. J. Watson Research Center Ashok Goel, Georgia Institute of Technology Russ Greiner, Siemens Corporate Research Walter Hamscher, Price Waterhouse Technology Centre Steve Hanks, University of Washington Caroline Hayes, Beckman Institute Barbara Hayes-Roth, Stanford University Jim Hollan, Bell Communications Research John Horty, University of Maryland Eric Horvitz, Rockwell Palo Alto Laboratory Larry Hunter, National Library of Medicine Yumi Iwasaki, Stanford University Randolph Jones, University of Pittsburgh Leo Joskowicz, IBM T. J. Watson Research Center Leslie Kaelbling, Brown University Michael Kahn, Washington University Subbarao Kambhampati, Arizona State University Richard Korf, University of California, Los Angeles Benjamin Kuipers, University of Texas at Austin Fangzhen Lin, Stanford University Matt Mason, Carnegie Mellon University David McAllester, Massachusetts Institute of Technology Kathy McCoy, University of Delaware David McKeown, Carnegie Mellon University Robert L. Mercer, University of Western Toronto David P. Miller, Massachusetts Institute of Technology Steve Minton, NASA Ames Research Center Dan Miranker, University of Texas at Austin Sanjay Mittal, Metaphor Computer Systems Michael Mozer, University of Colorado Ram Nevatia, University of Southern California Ramesh S. Patil, University of Southern California Michael Pazzani, University of California, Irvine Ed Pednault, AT&T Bell Laboratories Jordan Pollack, Ohio State University Martha Pollack, University of Pittsburgh Olivier Raiman, Xerox PARC Ashwin Ram, Georgia Institute of Technology Larry Rendell, University of Illinois Chuck Rich, Mitsubishi Electric Research Laboratories George Robertson, Xerox PARC Yves Schabes, University of Pennsylvania Jeff Schlimmer, Washington State University Bart Selman, AT&T Bell Laboratories Jude Shavlik, University of Wisconsin Mark Shirley, Xerox PARC Yoav Shoham, Stanford University Stephen F. Smith, Carnegie Mellon University Richard Sproat, AT&T Bell Laboratories Lynn Stein, MIT AI Lab Sal Stolfo, Columbia University Devika Subramanian, Cornell University Rich Sutton, GTE Laboratories Katia P. Sycara, Carnegie Mellon University Milind Tambe, Carnegie Mellon University Jeff Van Baalen, University of Wyoming Dan Weld, University of Washington Mike Wellman, Wright-Patterson Air Force Base Brian Williams, Xerox PARC Beverly Woolf, University of Massachusetts at Amherst Ken Yip, Yale University Auxiliary Reviewers Kristin Bennett, University of Wisconsin Gunnar Blix, University of Illinois Prasad Chalasani Kevin Cherkauer, University of Wisconsin Ken Church, AT&T Bell Laboratories Mark Craven, University of Wisconsin Brian Falkenhainer, Xerox PARC Tim Griffin Steve Hampson, University of California, Irvine Don Hindle Julia Hirschberg, AT&T Bell Laboratories Scott Hunter, Cornell University Rich Maclin, University of Wisconsin Ambuj Mahanti, University of Maryland Ganesh Mani, University of Wisconsin Dave Opitz, University of Wisconsin Peter Patel-Schneider, AT&T Bell Laboratories Fernando Pereira, AT&T Bell Laboratories Eduardo PeĢrez, University of Illinois Harish Ragavan Lisa Rau, General Electric Company Enrique H. Ruspini, SRI International Charles Squires David Tcheng, University of Illinois Larry Watanabe, University of Illinois Adam Webber, Cornell University Ron Williams, Northeastern University Der-Shung Yang, University of Illinois Derek Zahn AAAI Officials President: Patrick Hayes, Stanford University President-Elect: Barbara Grosz, Harvard University Past President: Daniel G. Bobrow, Xerox Palo Alto Research Center Secretary-Treasurer: Bruce Buchanan, University of Pittsburgh Councilors (through 1992) Kenneth D. Forbus, Northwestern University Howard Shrobe, Symbolics/MIT William Swartout, USC-ISI J. Martin Tenenbaum, EITech Councilors (through 1993) Mark Fox, University of Toronto Barbara Hayes-Roth, Stanford University Thomas Dietterich, Oregon State University Richard Fikes, Stanford University Councilors (through 1994) Jaime Carbonell, Carnegie Mellon University Paul Cohen, University of Massachusetts Elaine Kant, Schlumberger Laboratory for Computer Science Candy Sidner, Digital Equipment Corporation Standing Committees Conference Chair: William Swartout, University of Southern California– ISI Finance Chair: Bruce Buchanan, University of Pittsburgh Publications Chair: Mark Fox, University of Toronto Scholarship Chair: Barbara Hayes-Roth, Stanford University Symposium Chair: Peter Patel-Schneider, AT&T Bell Laboratories Symposium Cochair: James Hendler, University of Maryland Symposium Associate Chair: Paul Cohen, University of Massachusetts Workshop Grants Chair: Geoffrey Hinton, University of Toronto Workshop Grants Cochair: Candy Sidner, Digital Equipment Corporation AI in Medicine Subgroup Liaison: Gordon Banks, University of Pittsburgh AI in Manufacturing Subgroup Liaison: Karl Kempf, Intel AI and the Law Subgroup Liaison: Edwina Rissland, University of Massachusetts AI in Business Subgroup Liaison: Dan O’Leary, University of Southern California AAAI Staff Executive Director: Carol McKenna Hamilton Accountant: Julia G. Bowen Membership & Systems Coordinator: Richard A. Skalsky Conference Coordinator: Annette Eldredge Conference & Trade Show Coordinator: Mary Livingston Administrative: Hasina Aziz, Daphne Black, Sally McLaughlin, Arthur Okorie, and Godwin Okorie AI Magazine Staff Coeditor: Ramesh Patil, University of Southern California/ISI Coeditor: Elaine Rich, MCC Editor Emeritus: Robert Engelmore, Stanford University Associate Editor, Book Reviews: Bruce D’Ambrosio, Oregon State University Associate Editor, Workshop Reports: Peter Patel-Schneider, AT&T Bell Labs Associate Editor, Dissertation Abstracts: Peter Karp, SRI International Publishing Director: David Mike Hamilton, The Live Oak Press Managing Editor: Ellie Engelmore, AAAI Art Direction & Graphics: Dianne Erickson & Jim Marin, Spectra Media Production Editor: Sunny Ludvik, Ludvik Editorial Services The AAAI Press The MIT Press Coliaisons: Robert Prior and Teresa Ehling, The MIT Press Editor-in-Chief: William Clancey, Institute for Research on Learning General Manager: David Mike Hamilton, The Live Oak Press Management Board William Clancey, Institute for Research on Learning David Mike Hamilton, The Live Oak Press Robert Prior, The MIT Press Teresa Ehling, The MIT Press Reid Smith, Schlumberger Laboratory for Computer Sciences Editorial Board Ken Forbus, Northwestern University Tom Dietterich, Oregon State University Scott Fahlman, Carnegie Mellon University Jean-Claude Latombe, Stanford University John McDermott, Carnegie Mellon University Judea Pearl, University of California, Los Angeles Reid Smith, Schlumberger Laboratory for Computer Sciences Yoav Shoham, Stanford University Howard Shrobe, Symbolics/MIT J. Martin Tenenbaum, Stanford University Bonnie Webber, University of Pennsylvania AAAI Corporate Sponsors Digital Equipment Corporation General Motors Research Laboratory