ABSTRACT
In reading multiple texts, a reader must integrate information from the texts with his or her background knowledge. The resulting situation model represents a rich elaborated structure of events, actions, objects, and people involved in the text organized in a manner consistent with the reader's knowledge. In order to evaluate a reader's situation model, a reader's summary must be analyzed in relation to texts the subject has read as well as to more general knowledge such as an expert's knowledge. However, this analysis can be both time-consuming and difficult. In this paper, we use an automatic approach called Latent Semantic Analysis (LSA) for evaluating the situation model of readers of multiple documents. LSA is a statistical model of word usage that generates a high-dimensional semantic space that models the semantics of the text. This paper describes three experiments. The first two describe methods for analyzing a subject's essay to determine from what text a subject learned the information and for grading the quality of information cited in the essay. The third experiment analyzes the knowledge structures of novice and expert readers and compares them to the knowledge structures generated by the model. The experiments illustrate a general approach to modeling and evaluating readers' situation models.
