Proceedings of the Annual Meeting of the Cognitive Science Society

In an earlier study, we modeled subjects' beliefs in textually embedded propositions with E C H O , a computational system for simulating explanatory evaluations (Schank & Ranney, 1991). W e both presumed and found that subjects' representations of the texts were not completely captured by the (a priori) representations generated and encoded into E C H O ; extraneous knowledge likely contributed to subjects' biases toward certain hypotheses. This study builds on previous work via two questions: First, h o w well can E C H O predict subjects' belief evaluations when a priori representations are not used? To assess this, w e asked subjects to predict (and explain, with alternatives) an endpoint pendular-release trajectory, while collecting believability ratings for their on-line beliefs; subjects' protocols were then "blindly" encoded and simulated with E C H O , and their ratings were compared to ECHO'S resulting activations. Second, how similar are different coders' encodings of the same reasoning episode? T o assess intercoder agreement, w e examined the fit between ECHO'S activations for coders' encodings of the same protocols. W e found that intercoder correlations were acceptable, and E C H O predicted subjects' ratings well—almost as well as those from the more diminutive, constrained situations modeled by Schank and Ranney (1991).