In Coherence and Natural Language, Florian Wolf and Edward Gibson specify and evaluate criteria for descriptively adequate data structures for representing discourse coherence. They test the influence of discourse structure on pronoun processing, evaluate different approaches for determining the relative importance of document segments, and propose a new coherence-based algorithm to accomplish this task. Their book offers the first large-scale empirical evaluation of data structures for representing coherence and also includes novel psycholinguistic tests of existing information extraction and text summarization systems.
Wolf and Gibson evaluate whether tree structures are descriptively adequate for representing discourse coherence and conclude that more powerful data structure is needed because there are many different kinds of crossed dependencies and nodes with multiple parents in the discourse structures of naturally occurring texts. They propose that connected, labeled chain graphs make a better representation of coherence. They find additionally that causal coherence relations affect people's strategies for pronoun processing, which points to the psychological validity of coherence relations. Finally, they evaluate word-based, layout-based, and coherence-based approaches for estimating the importance of document segments in a document and find that coherence-based methods that operate on chain graphs perform best. With its attention to empirical validation and psycholinguistic processing, the book raises issues that are relevant to cognitive science as well as natural language processing and information extraction.
About the Authors
Florian Wolf has started his own company in Munich, Germany, and is developing algorithms for information management.
Edward Gibson is Professor of Cognitive Science in the Department of Brain and Cognitive Sciences at MIT.
"In its biggest step forward since Aristotle, research on discourse structure has come down to earth by combining analysis of real-world text corpora with data about human readers. Wolf and Gibson's book documents and advances the state of our knowledge in today's liveliest area of linguistic analysis."
—Mark Liberman, Director, Linguistic Data Consortium, University of Pennsylvania
"An extensive analysis of discourse coherence that is at once theoretically motivated and empirically driven, with demonstrated applications to problems in both computational linguistics and psycholinguistics."
—Andrew Kehler, Department of Linguistics, University of California, San Diego