Teaching by Examples: Implications for the Process of Category Acquisition

A new paradigm, the “teaching-by-examples” paradigm, was used to shed new light on the process of category acquisition. In four experiments ( n = 90, 90, 115, 117), manipulating the variables of category structure, status of non-target category, learning mode, and teaching mode, participants first learned a category and then taught it to someone else. High agreement between participants on the teaching sequences was found across conditions, and a typical sequence was identified for each category structure. The typical participant-produced sequences started with several ideal positive cases, followed by an ideal negative case and then borderline cases. The efficiency of such sequences for teaching was tested in another experiment ( n = 60), in which they were compared with sequences emphasizing category borders and sequences emphasizing each dimension separately. The typical participant-produced sequences induced the most efficient learning. It is proposed that the pattern of performance may provide a rich source of data for testing and fine-tuning models of category acquisition.