Proceedings of the Annual Meeting of the Cognitive Science Society

The problem of evaluating explanatory hypotheses is to choose the hypothesis or theory that best accounts for, or explains, the given evidence. Thagard (e.g.. 1989) and Ranney (in press; Ranney & Thagard, 1988) describe a theory of explanatory coherence intended to account for a variety of explanatory evaluations; this theory has been implemented in a coimectionist computer model, ECHO. In this study, we examine three questions regarding the relationship between human explanatory reasoning and echo's explanatory evaluations: Does E C H O predict subjects' evaluations of interrelated propositions? Are local temporal order differences (not explicitly modeled by ECHO) important to the subjects? Does E C H O predict subjects' inflectional reasoning? W e found that subjects often entertain competing hypodieses as nonexclusive and presume an implied backing for certain (superordinate) hypotheses. These tendencies were modeled in E C H O by assigning a fraction of data priority (usually reserved for evidence) to the superordinate hypotheses. In simi, the E C HO model helps to interpret subjects' reasoning patterns, and shows continued potential for simulating explanatory coherence processes.