Date: Sat 27 Aug 1988 00:30-EDT From: AIList Moderator Nick Papadakis Reply-To: AIList@mc.lcs.mit.edu Us-Mail: MIT LCS, 545 Tech Square, Rm# NE43-504, Cambridge MA 02139 Phone: (617) 253-6524 Subject: AIList Digest V8 #69 To: AIList@mc.lcs.mit.edu Status: R AIList Digest Saturday, 27 Aug 1988 Volume 8 : Issue 69 Seminars: Acquiring a Model of the User's Beliefs Software Reusability: An Intelligent Approach Localized Event-based Planning For Multiagent Domains - Amy Lansky Describing Program Transformers with Higher-order Unification ---------------------------------------------------------------------- Date: Fri, 12 Aug 88 11:16:43 EDT From: finin@PRC.Unisys.COM Subject: Acquiring a Model of the User's Beliefs ... Ph.D. Dissertation Defense Acquiring a Model of the User's Beliefs from a Cooperative Advisory Dialogue Robert Kass The ability of expert systems to explain their own reasoning is often cited as their most important feature. Unfortunately, the quality of these explanations is frequently poor. In this talk, I will argue that for expert systems to produce good explanations, they must have available a model of the user's beliefs about the system domain. Obtaining such a model is not easy, however. Traditional approaches have depended on the explicit hand-coding of a large number of assumptions about the beliefs of anticipated system users -- a tedious and error-prone process. In contrast, I will present an implicit method for acquiring a user model, embodied in a set of implicit user model acquisition rules. These rules, developed from the study of a large number of transcripts of people seeking advice from a human expert, represent likely inferences that can be made about a user's beliefs -- based on the system-user dialogue and the dialogue participants' previous beliefs. This implicit acquisition method is capable of quickly building a substantial model of the user's beliefs; a model sufficient to support the generation of expert system explanations tailored to individual users. Furthermore, the acquisition rules are domain independent, providing a foundation for a general user modelling facility for a variety of interactive systems. Committee: Tim Finin (Advisor) Aravind Joshi (Chairman) Elaine Rich (MCC) Bonnie Webber Date: Monday, August 15, 1988 Time: 3:00 - 5:00 p.m. Location: 554 Moore, University of Pennsylvania ------------------------------ Date: Mon, 15 Aug 88 10:59:12 EDT From: finin@PRC.Unisys.COM Subject: Software Reusability: An Intelligent Approach (UNISYS) Software Reusability: An Intelligent Approach Mark A. Simos and James Solderitsch Software Technology Department UNISYS Paoli Research Center GVL-2 Auditorium Unisys Great Valley Labs 12:00-1:00, 15 August 1988, The topic of software reusability has been at the forefront of software engineering research for quite some time, but as yet has failed to live up to initial expectations. Part of the reason for this failure was early and lingering confusion about the subjects of software engineering and software reusablity, and the belief that the proper software engineering methodology, and perhaps even the right programming language, would naturally and effortlessly lead to the creation of reusable software. Recent research has begun to pinpoint the unique issues relating explicitly to software reusability. This talk describes a practical approach to software reuse based on the incremental development of intelligent libraries of reusable components. Such libraries, or repositories, are structured around explicit domain models which are knowledgebased frameworks providing taxonomic representations of specific application domains. These frameworks provide a uniform view of both static software components and generative capabilities, and contain tools to actively guide users in browsing among and selecting existing components, or classifying and qualifying new candidate components for the repository. After an introduction to some of the essential issues of software reusability, we present some background motivation for a domain-specific focus to reusability. We next discuss the use of program generation and knowledge-based techniques that support domain-specificity and sketch the evolution of the development of a reuse library based on these techniques. We close with a description of our current project that is directed at developing the basic Reusability Library Framework (RLF) technology necessary for the development of such domainspecific libraries. The RLF project is sponsored by the STARS Ada Foundations Technology program (contract number N00014-88-C-2052). Specific objectives of the RLF project include providing a set of knowledge-based components in Ada that support the creation and maintenance of domain models, and the development, using this platform, of general library tools for component testing, qualification and retrieval. ------------------------------ Date: Tue, 23 Aug 88 09:33:11 PDT From: CHIN%PLU@ames-io.ARPA Subject: Localized Event-based Planning For Multiagent Domains - Amy Lansky *************************************************************************** National Aeronautics and Space Administration Ames Research Center SEMINAR ANNOUNCEMENT SPEAKER: Amy L. Lansky SRI International TOPIC: LOCALIZED EVENT-BASED PLANNING FOR MULTIAGENT DOMAINS ABSTRACT: This talk will present the GEM concurrency model and GEMPLAN, a multiagent planner based on this model. Unlike standard state-based AI representations, GEM is unique in its explicit emphasis on events and domain structure -- world activitiy is modeled in terms of events occurring within a set of regions. Event-based temporal logic constraints are then associated with each region to delimit legal domain behavior. GEM's emphasis on constraints is directly reflected in the architecture of the GEMPLAN planner -- it can be viewed as a general purposed constraint satisfaction facility. Its task is to construct a network of interrelated events that satisfies all applicable regional constraints and also achieves some stated goal. A key focus of our work has been on the use of --localized--techniques for domain representation and reasoning. Such techniques partition domain descriptions and reasoning tasks according to the regions of activity within a domain. For example, GEM localizes the applicability of domin constraints and also imposes additional "locality constraints" based on domain structure. This use of locality helps alleviate several aspects of the frame problem for multiagent domains. The GEMPLAN planner also reflects the use of locality; its constraint satisfaction search space is subdivided into regional planning search spaces. GEMPLAN can pinpoint and rectify interactions among these regional search spaces, thereby reducing the burden of "interaction analysis" ubiquitous to most planning systems. DATE: Wednesday TIME: 2:00 pm - 3:30 pm BLDG. 244 Room 103 August 31, 1988 -------------- POINT OF CONTACT: Marlene Chin PHONE NUMBER: (415) 694-6527 NET ADDRESS: chin@pluto.arc.nasa.gov *************************************************************************** VISITORS ARE WELCOME: Register and obtain vehicle pass at Ames Visitor Reception Building (N-253) or the Security Station near Gate 18. Do not use the Navy Main Gate. Non-citizens (except Permanent Residents) must have prior approval from the Director's Office one week in advance. Submit requests to the point of contact indicated above. Non-citizens must register at the Visitor Reception Building. Permanent Residents are required to show Alien Registration Card at the time of registration. *************************************************************************** ------------------------------ Date: Fri, 26 Aug 88 09:47:31 EDT From: finin@PRC.Unisys.COM Subject: Describing Program Transformers with Higher-order Unification AI SEMINAR UNISYS PAOLI RESEARCH CENTER Describing Program Transformers with Higher-order Unification John J. Hannan Computer and Information Science University of Pennsylvania Source-to-source program transformers belong to the class of meta-programs that manipulate programs as objects. It has previously been argued that a higher-order extension of Prolog, such as Lambda-Prolog, makes a suitable implementation language for such meta-programs. In this paper, we consider this claim in more detail. In Lambda-Prolog, object-level programs and program schemata can be represented using simply typed lambda-terms and higher-order (functional) variables. Unification of these lambda-terms, called higher-order unification, can elegantly describe several important meta-level operations on programs. We detail some properties of higher-order unification that make it suitable for analyzing program structures. We then present (in Lambda-Prolog) the specification of several simple program transformers and demonstrate how these can be combined to yield more general transformers. With the depth-first control strategy of Lambda-Prolog for both clause selection and unifier selection all the above mentioned specifications can be and have been executed and tested. 2:00 pm Wednesday, August 3 Unisys Paloi Research Center BIC Conference Room Route 252 and Central Ave. Paoli PA 19311 -- non-Unisys visitors who are interested in attending should -- -- send email to finin@prc.unisys.com or call 215-648-7446 -- ------------------------------ End of AIList Digest ********************