APPLAUSE: An implementation of the Collins-Michalski theory of plausible reasoning

Abstract

Ability to make decisions in situations not encountered before characterizes human reasoning. This paper discusses a pilot implementation of the computational model of human plausible reasoning proposed by Collins and Michalski. The model assumes that human knowledge can be represented as objects or concepts that are related by similarity, generalization and specialization relations and are arranged into hierarchies. Facts about the world are represented as traces linking nodes of different hierarchies. The building of the hierarchies and construction of the links is an integral part of the learning process undergone by human beings. Plausible reasoning is an ability to draw inferences when direct links between concerned objects are not available. This involves perturbation of established traces and traversal through the concerned hierarchies, inheritance of the properties along the way, and combination of evidence for selection of the best inference. A pilot version of the theory of plausible reasoning has been implemented in a system called applause(for approximate/ Plausibl e reasoning). Some key operations are illustrated with the examples from the domain of the chemical periodic table.