 Christel Kemke 2007/08 COMP 4060 Natural Language Processing Discourse and Dialogue

2007/08  Christel Kemke Discourse and Dialogue Discourse Phenomena Speech Acts Dialogue Acts

2007/08  Christel Kemke Discourse Discourse = collocated, related group of sentences Monologues and Dialogues Referring Expressions: he, she Coherence Discourse Structure see Jurafsky and Martin, Ch. 18 and 19

2007/08  Christel Kemke Reference Referring Expressions Referent the Jurafsky the 406 textbook

2007/08  Christel Kemke Reference Discourse Model - keeps track of representations of entities mentioned in discourse so far Referring Expression - encodes information / signals for hearer to identify referent Methods: Determine mapping from sign in referring expression to set of beliefs / discourse model of hearer. Referents can be different parts, aspects of a sentence or utterance. Use constraints on co-reference (syntax, discourse) to determine mapping.

2007/08  Christel Kemke Reference "According to John, Bob bought Sue an Integra, and Sue bought Fred a Legend." a) But that turned out to be a lie. speech act b) But that was false. proposition c) That caused Sue to become rather poor. event d) That caused both of them to become rather poor. combination of events

2007/08  Christel Kemke Reference Indefinite / definite noun phrases specific / non-specific entity Pronouns salience (last mentioned) cataphora (pronoun mentioned before entity) bound in context of "quantified variable" Demonstratives (this, that) "spatial proximity" (metaphorically), e.g. old - new car

2007/08  Christel Kemke Coherence Coherence Relations (Hobbs) – model "connectedness" of sentences in text Result John bought an Acura. His father went ballistic. Explanation John hid Bill's car keys. He was drunk. Parallel John bought an Acura. Bill leased a BMW. Elaboration John bought an Acura this weekend. He purchased a new beautiful Acura for... on Saturday afternoon. Occasion John bought an Acura. He drove to the ballgame.

2007/08  Christel Kemke Discourse Structure Arrangement of sentence elements into (coherent) text / analysis of text according to coherence relations Jurafsky and Martin, Figure 18.10, p. 705

 Christel Kemke 2007/08 Speech Acts

2007/08  Christel Kemke Three Aspects of Speech Acts Locutionary: the literal meaning of the utterance Illocutionary: the social function that the utterance or written text has (e.g. informing, ordering, warning, undertaking.) Perlocutionary: the result or effect that is produced by the utterance in that given context (e.g. convincing, persuading, deterring.)

2007/08  Christel Kemke Illocutionary Acts Assertives Directives Commissives Permissives Prohibitives Declaratives

2007/08  Christel Kemke Speech Acts Assertives committing the speaker to something's being the case “The door is shut.” Directives attempts by the speaker to get the addressee to do something “Shut the door.” Commissives committing the speaker to some future course of action “I will shut the door.” Expressives expressing the psychological state of the speaker about a state of affairs "Thanks for shutting the door."

2007/08  Christel Kemke Speech Acts Permissives allow / permit the hearer to a course of action as described by the propositional content of the utterance "You may shut the door." Prohibitives deny the hearer to a course of action as described by the propositional content "Don't shut the door." Declarations / Declaratives bringing about a different state of the world via the utterance "You're fired."

2007/08  Christel Kemke DAMSL - Dialogue Act Markup in Several Layers Statement Info-request Check Influence on Addressee Influence on Speaker Offer Commit Conventional Opening...

2007/08  Christel Kemke Questions and Frames

2007/08  Christel Kemke Reference Dan Jurafsky and James H. Martin, Speech and Language Processing, 1 st Edition, Chapters 18 and 19, Prentice-Hall, 2000