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Recent explanalion-based learning (EBL) models in Al allow a computer program to learn aschema by analyzing a single example. For example. GENESIS is an EBL system which learns a planschema from a single specific instance presented in a narrative. Previous learning models in both Aland psychology have required multiple examples. This paper presents experimental evidence thatpeople can learn a plan schema from a single narrative and that the learned schema agrees with thatpredicted by EBL. This evidence suggests that GENESIS, originally constructed as a machine learningsystem, can be interpreted as a psychological model of learning a complex schema from a singleexample.

Models of learning word meanings have generally assumed prior knowledge of the concepts to which the words refer. However, novel natural language text or discourse can often present both unknown concepts and words which refer to these concepts. Also, developmental data suggests that the learning of words and their concepts frequently occurs concurrently instead of concept learning proceeding word learning. This paper presents an integrated computational model for acquiring both word meanings and their underlying concepts concurrently. This model is implemented as a word learning component added to the CI-NLSIS explanation-based schema acquisition system for narrative understanding. A detailed example is described in which CnNHSIS learns provisional definitions for the words "kidnap", "kidnapper", and "ransom" as well as a kidnapping schema from a single narrative.

This study compares Similarity-Based Learning (SBL) and Explanation-Based Learning (EBL) approaches to schema acquisition. In SBL approaches, concept formation is based on similarity across multiple examples. However, these approaches seem to be appropriate when the learner cannot apply existing knowledge and when the concepts to be learned are nonexplanatory. EBL approaches assume that a schema can be acquired from even a single example by constructing an explanation of the example using background knowledge, and generalizing the resulting explanation. However, unlike the current EBL theories, Experiment 1 showed significant EBL occurred only when the background information learned during the experiment was actively used by the Ss. Experiment 2 showed the generality of EBL mechanisms across a variety of materials and test procedures.