Towards a paradigm shift in belief representation methodology

Abstract

Research programs must often divide issues into manageable sub-issues. The assumption is that an approach developed to cope with a sub-issue can later be integrated into an approach to the whole issue—possibly after some tinkering with the sub-approach, but without affecting its fundamental features. However, the present paper examines a case where an AI issue has been divided in a way that is, apparently, harmless and natural, but is, actually, fundamentally out of tune with the realities of the issue. As a result, some approaches developed for a certain sub-issue cannot be extended to a total approach without fundamental modification. The issue in question is that of representing and reasoning about people's beliefs, hopes, intentions and other ‘propositional attitudes’, and/or interpreting natural language sentences that report propositional attitudes. Researchers have, quite understandably, de-emphasized the problem of dealing in detail with nested attitudes (e.g., hopes about beliefs, beliefs about intentions about beliefs), in favour of concentrating on the sub-issue of non-nested attitudes. Unfortunately, a wide variety of approaches to attitudes are prone to a deep but somewhat subtle problem when they are applied to nested attitudes. This problem can be very roughly described as an AI system's unwitting imputation of its own arcane ‘theory’ of propositional attitudes to other agents. The details of this phenomenon have been published elsewhere by the author: the present paper therefore merely sketches it, and concentrates instead on the methodological lessons to be drawn, both for propositional attitude research and, more tentatively, for AI in general. The paper also summarizes an argument (presented more completely elsewhere) for an approach to attitude representation based in part on metaphors of mind that are commonly used by people. This proposed new research direction should ultimately coax propositional attitude research out of the logical armchair and into the psychological laboratory.

Keywords:

• belief representation
• propositional attitudes
• iterated attitudes
• com-monsense reasoning
• metaphors of mind
• AI methodology