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    Contingent necessity versus logical necessity in categorisation

    Pothos, E.M. and Hahn, Ulrike and Prat-Sala, M. (2010) Contingent necessity versus logical necessity in categorisation. Thinking and Reasoning 16 (1), pp. 45-65. ISSN 1354-6783.

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    Critical (necessary or sufficient) features in categorisation have a long history, but the empirical evidence makes their existence questionable. Nevertheless, there are some cases that suggest critical feature effects. The purpose of the present work is to offer some insight into why classification decisions might misleadingly appear as if they involve critical features. Utilising Tversky's (1977) contrast model of similarity, we suggest that when an object has a sparser representation, changing any of its features is more likely to lead to a change in identity than it would in objects that have richer representations. Experiment 1 provides a basic test of this suggestion with artificial stimuli, whereby objects with a rich or a sparse representation were transformed by changing one of their features. As expected, we observed more identity judgements in the former case. Experiment 2 further confirms our hypothesis, with realistic stimuli, by assuming that superordinate categories have sparser representations than subordinate ones. These results offer some insight into the way feature changes may or may not lead to identity changes in classification decisions.


    Item Type: Article
    Keyword(s) / Subject(s): Categorization, Critical features, Similarity
    School: Birkbeck Faculties and Schools > Faculty of Science > School of Psychological Sciences
    Research Centres and Institutes: Birkbeck Knowledge Lab
    Depositing User: Administrator
    Date Deposited: 09 May 2013 09:51
    Last Modified: 02 Aug 2023 17:03


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