Statistical foundations for default reasoning

  • Authors:
  • Fahiem Bacchus;Adam J. Grove;Joseph Y. Halpern;Daphne Koller

  • Affiliations:
  • Computer Science Dept., University of Waterloo, Waterloo, Ontario, Canada;NEC, Research Inst., Princeton, NJ;IBM Almaden Research Center, San Jose, CA;Computer Science Dept., Stanford University, Stanford, CA

  • Venue:
  • IJCAI'93 Proceedings of the 13th international joint conference on Artifical intelligence - Volume 1
  • Year:
  • 1993

Quantified Score

Hi-index 0.00

Visualization

Abstract

We describe a new approach to default, reasoning, based on a principle on indifference among possible worlds. We interpret default rules as extreme statistical statements, thus obtaining a knowledge base KB comprised of statistical and first-order statements. We then assign equal probability to all worlds consistent with KB in order to assign a degree of belief to a statement Φ. The degree of belief can be used to decide whether to defeasibly conclude Φ. Various natural patterns of reasoning, such as a preference for more specific defaults, indifference to irrelevant information, and the ability to combine independent pieces of evidence, turn out to follow naturally from this technique. Furthermore, our approach is not restricted to default reasoning; it supports a spectrum of reasoning, from quantitative to qualitative. It is also related to other systems for default reasoning. In particular, we show that the work of [Goldszmidt et al., 1990], which applies maximum entropy ideas to --semantics, can be embedded in our framework.