Editing Cognitive categorization (section)

===Exemplar theory===
{{main|Exemplar theory}}
Another instance of the similarity-based approach to categorization, the exemplar theory likewise compares the similarity of candidate category members to stored memory representations. Under the exemplar theory, all known instances of a category are stored in memory as exemplars. When evaluating an unfamiliar entity's category membership, exemplars from potentially relevant categories are retrieved from memory, and the entity's similarity to those exemplars is summed to formulate a categorization decision.<ref name="Kruschke, J. K. 2008"/> Medin and Schaffer's (1978) [[Context model]] employs a [[Nearest neighbor cluster|nearest neighbor]] approach which, rather than summing an entity's similarities to relevant exemplars, multiplies them to provide weighted similarities that reflect the entity's proximity to relevant exemplars.<ref name="Medin, D. L. 1978">{{Cite journal |last1=Medin |first1=Douglas L. |last2=Schaffer |first2=Marguerite M. |year=1978 |title=Context theory of classification learning.|url=http://doi.apa.org/getdoi.cfm?doi=10.1037/0033-295X.85.3.207|journal=Psychological Review |volume=85 |issue=3 |pages=207–238 |doi=10.1037/0033-295X.85.3.207 |s2cid=27148249 |issn=1939-1471}}</ref> This effectively biases categorization decisions towards exemplars most similar to the entity to be categorized.<ref name="Medin, D. L. 1978"/><ref>Goldstone, R. L., Kersten, A., & Carvalho, P. F. (2012). Concepts and categorization. Handbook of Psychology, Second Edition, 4.</ref>