PACKER: An Exemplar Model of Category Generation.

Generating new concepts is an intriguing yet understudiedtopic in cognitive science. In this paper, we present a novelexemplar model of category generation: PACKER (ProducingAlike and Contrasting Knowledge using Exemplar Representa-tions). PACKER’s core design assumptions are (1) categoriesare represented as exemplars in a multidimensional psycholog-ical space, (2) generated items should be similar to exemplarsof the same category, and (3) generated categories should bedissimilar to existing categories. A behavioral study revealsstrong effects of contrast- and target-class similarity. Theseeffects are novel empirical phenomena, which are directly pre-dicted by the PACKER model but are not explained by existingformal approaches.