Analogy as Functional Recategorization: A Perspective from HowNet Tony Veale Department of Computer Science, University College Dublin, Belfield, Dublin 6, Ireland. Tony.veale@UCD.ie http://www.cs.ucd.ie/staff/tveale/home/ Abstract. One generally accepted hallmark of creative thinking is an ability to look past conventional labels to recategorize a concept or object based on its behaviour and functional potential. So while taxonomies are useful in any domain of reasoning, they typically represent the conventional label set that creative thinking attempts to look beyond. If a linguistic taxonomy like WordNet [1] is to be useful in driving linguistic creativity, it must support some basis for recategorization, to allow an agent to reorganize its category structures in a way that unlocks the functional potential of objects, or that recognizes similarity between literally dissimilar ideas. In this paper we consider how recategorization can be used to generate analogies using the HowNet [2] ontology, a lexical resource like WordNet that in addition to being bilingual (Chinese/English) also provides explicit semantic definitions for each of the terms that it defines. 1 Introduction Analogy is a knowledge-hungry process that exploits a conceptual system’s ability to perform controlled generalization in one domain and re-specialization into another. The result is a taxonomic leap within an ontology that transfers semantic content from one term onto another. While all taxonomies allow vertical movement, a system must fully understand the effects of generalization on a given concept before any analogy or metaphor can be considered either deliberate or meaningful. Research has shown that the most satisfying analogies are those that operate at the causal level of representation, since causality allows an analogy to offer an deep explanation of a poorly understood phenomenon (e.g., [3], [4]). Thus, the atom as miniature solar- system is satisfying because the source and target concepts are causally structured around the notion of rotation. So to support analogy, a taxonomy must provide a basis of abstracting over the causal behaviour of concepts. When comparing agents or artefacts, this causality can be abstracted out by considering the functional or behavioural commonality between target and source: a surgeon can be meaningfully described as a repairman since both occupations have the function of restoring an object to an earlier and better state; a footballer can be