Analogy has traditionally been defined in terms of a contrast definition: analogies represent connections between things which are distinct from the 'normal' connections determined by our 'ordinary' concepts and categories. In this paper we present empirical evidence which, when added to other findings, supports our argument that in the light of current knowledge, the distinction between the two is based more on folk-psychology than on empirically based theory. Research into analogy is however, distinct from research into categorisation when it comes to the richness of its process models. A number of detailed, plausible models of the analogical process exist (Forbus, Centner and Law, 1995; Holyoak and Thagard. 1995): the same cannot be said of categorisation. On the other hand, these analogical process models make a number of explicit and implicit assumptions regarding an 'extemal' categorical process. Whilst treating these processes as separate has been useful in constraining the scope of cognitive investigations, we argue that it ultimately confuses the relationship between analogy and categorisation and is hampering the progress towards further understanding of both.

We argue that the key question in conceptual storage is best viewed not as a question of instances versus generalisations, but rather one of unitary versus multiple representation accounts of conceptual storage. On previous evidence, it has been difficult to determine whether a particular result stems from stored information regarding the concept or from the processes that operate in invoking a particular concept (Komatsu, 1992). In this paper, we attempt to shed some light on the nature of stored conceptual structure using the different influences that surface and stmctural features have been shown to have on the recall of a particular representation (Centner, Ratterman and Forbus, 1993). We conclude that at least some concepts may not be stored using a unitary representation.