The (CSCW '86) was held in Austin, participants). The three-day report introduces the field of computersupported Texas, on 3-5 December 1986. It was event included nine paper sessions: cooperative work, describes the sponsored by the Microelectronics supporting face-to-face groups, empirical CSCW '86 program, and discusses the significance and Computer Technology Corporation studies, supporting distributed of the conference results An (MCC) Software Technology Program groups, hypertext systems, underlying introduction to the follow-on conference, in cooperation with the Association technology for collaborative systems, CSCW '88, is also provided for Computing Machinery (ACM) collaboration research, multimedia and its special interest groups on software and multiuser interfaces, industrial engineering (SIGSOFT), human experiences with CSCW, and coordination computer interaction (SIGCHI), and and decision making. There office information systems (SIGOIS); were also four panel sessions; the topics the Institute for Electrical and Electronic were collaboration and offices, collaborative Engineers (IEEE) Computer design studies, from theories Society; the American Association for to systems, and trends and markets Artificial Intelligence (AAAI); The for computer-supported group Information Management Society work. As the invited dinner speaker, (TIMS); and the Software Psychology Robert Howard, noted author on the Society.

This article presents an approach to a graduate-level course in expert, knowledge-based, problem-solving systems. The core of the course, and this article, is a set of questions called a profile, that can be used to characterize and compare each system studied.

Krasner is the author of Department of Neurology at the University the "CSCW '86 Summary Report." of California at Davis.

This article examines the direction in which knowledge bases are constructed for diagnosis and decision making. When building an expert system, it is traditional to elicit knowledge from an expert in the direction in which the knowledge is to be applied, namely, from observable evidence toward unobservable hypotheses. However, experts usually find it simpler to reason in the opposite direction-from hypotheses to unobservable evidence-because this direction reflects causal relationships. Therefore, we argue that a knowledge base be constructed following the expert's natural reasoning direction, and then reverse the direction for use. This choice of representation direction facilitates knowledge acquisition in deterministic domains and is essential when a problem involves uncertainty. We illustrate this concept with influence diagrams, a methodology for graphically representing a joint probability distribution. Influence diagrams provide a practical means by which an expert can characterize the qualitative and quantitative relationships among evidence and hypotheses in the apporiate direction. Once constructed, the relationships can easily be reserved into the less intuitive direction in order to perform inference inference and diagnosis. In this way, knowledge acquisition is made cognitively simple; the machine carries the burden of translating the representation.

The questions of how humans process uncertain information is important to the development of knowledge-based systems in term of both knowledge acquisition and knowledge representation. This article reviews three bodies of psychological research that address this question: human perception, human probabilistic and statistical judgement, and human choice behavior. The general conclusion is that human behavior under certainty is often suboptimal and sometimes even fallacious. Suggestions for knowledge engineers in detecting and obviating such errors are discussed. The requirements for a system designed to reduce the effects of human factors in the processing of uncertain knowledge are introduced.

The First International Workshop on User Modeling in Natural Language Dialogue Systems was held 30-31 August 1986 in Maria Laach, West Germany. Issues addressed by the participants included the appropriate contents of a user model, techniques for constructing user models in both understanding and generating natural language dialogue, and the development of general user-modeling systems. This article includes an overview of the presentations made at the workshop. It is a compilation of the author's impressions and observations and is, therefore, undoubtedly incomplete; and at times might fail to accurately represent the views of the researcher presenting the work.

The 1987 Workshop on Distributed Artificial Intelligence (DAI) was held at Sea Ranch, California, 3 to 6 December 1987. Twenty-eight participants gathered in this rugged, windswept northern California coastal village to debate the theory and practice of DAI.

This article discusses several effective techniques for expert system knowledge acquisition based on the techniques that were successfully used to develop the Central Office Maintenance Printout Analysis and Suggestion System (COMPASS). Knowledge acquisition is not a science, and expert system developers and experts must tailor their methodologies to fit their situation and the people involved. Developers of future expert systems should find a description of proven knowledge-acquisition techniques and an account of the experience of the COMPASS project in applying these techniques to be useful in developing their own knowledge-acquisition procedures.

Even though sues raised during the workshop sponsored emerged during the workshop. In many situations, users are not sufficiently defined or Seattle, Washington. Issues include the need guidance and counseling in order understood to be amenable to traditional definition of coupled systems, motivations to solve the problem at hand. In control system--one that combines such situations, users often need help techniques from artificial intelligence in determining which specific algorithm (AI), control theory, and operations or technique should be research (Kowalik et al. 1986). In other situations, traditional techniques to perform the need is more basic--for guidance in many routine tasks, sophisticated determining whether the problem at hand can be solved and, if so, whether techniques are needed to handle many the resources that can be brought to of the humanlike functions.

We describe a computer program that implements an algorithm to verify the consistency and completeness of knowledge bases built for the Lockheed expert system (LES) shell. The algorithms described here are not specific to this particular shell and can be applied to many rule-based systems. The computer program, which we call CHECK, combines logical principles as well as specific information about the knowledge representation formalism of LES. The program checks both goal-driven and data-driven rules. CHECK identifies inconsistencies in the knowledge base by looking for redundant rules, conflicting rules, subsumed rules, unnecessary IF conditions, and circular rule chains. Checking for completeness is done by looking for unreferenced attribute values, illegal attribute values, dead-end IF conditions, dead-end goals and unreachable conclusions. These conditions can be used to suggest missing rules and gaps in the knowledge base. The program also generates a chart that shows the dependencies among the rules. CHECK can help the knowledge engineer detect many programming errors even before the knowledge base testing phase. It also helps detect gaps in the knowledge base testing phase. It also helps detect gaps in the knowledge base that the knowledge engineer and the expert have overlooked. A wide variety of knowledge bases have been analyzed using CHECK.