Computational modeling of discourse comprehension

Cover illustration: Jip en Janneke voetballen met de situatieruimte [Bob and Jilly play soccer with situation space] by the author, after a drawing by Fiep Wes-tendorp. No human inquiry can be a science unless it pursues its path through mathematical exposition and demonstration 5 Extending the DSS model 147 5.1 Story retention 148 5.2 Pronoun resolution 153 5.3 Towards a textbase-level representation 169 6 Summary and conclusions 181 6.1 Summary 181 6.2 Conclusions 188 References 191 Appendices 201 A Simulation details 202 B Mathematical details 206 Samenvatting 211 Nawoord 221 Curriculum Vitae 223 1 Introduction Sentences rarely occur in isolation. Usually, a sentence forms part of a discourse and cannot be fully understood without relating it to the other discourse statements. As an example, the story A Snowman with a Broom by Annie M.G. Schmidt (1963), meant for children aged five years and up, begins with the following six sentences: Father, how do you make a snowman? Bob asks. I will help you, father says. He takes a shovel from the shed. And Bob gets a small shovel. And so does Jilly. And then they work very hard. (p. 46. Translated from Dutch) Although the story is very easy to understand, making sense of any individual sentence is impossible without using information from the rest of the text and, often, the reader's or listener's general knowledge. Under normal conditions , this part of language comprehension proceeds automatically and without much effort. For instance, without being mentioned explicitly it is immediately understood from the above story fragment that Father says that father will help Bob make a snowman. Father takes a shovel from the shed in order to help Bob make a snowman. Bob gets a small shovel from his father. Jilly gets a small shovel from Bob's father. Bob, Jilly, and Bob's father work very hard on making a snowman. This list is far from exhaustive. For instance, it does not say anything about the order in which all these events occur, about the fact that there must be snow around, or about the likelihood that the snowman will get a carrot for a nose. Many of such inferences need to be drawn in order to comprehend the story, and most readers and listeners do understand simple stories without engaging in any conscious problem solving. This cognitive process of discourse comprehension forms the topic of this thesis. In particular, the …