Proceedings of the Annual Meeting of the Cognitive Science Society

We suggest that human learners employ both similarity-based learning (SBL) and explanation-based learning (EBL) procedures and that the successful use of these procedures is determined by the characteristics of the information to be learned. In a domain without underlying causal structure, multiple examples can lead to successful SBL, but not to successful EBL. In a domain with underlying causal structure, the use of appropriate background knowledge can lead to successful EBL, but not to SBL. A series of experiments was carried out in which a common initial passage was followed with a variety of different types of information (a second similar instance, a second contrasting instance, frequency data, or explanations). EBL occurred only when subjects had sufficient background knowledge and when the information to be learned could be causally structured. SBL occurred when there were multiple examples, even in domains without causal structure.