discourse and dialogue

discourse and dialogue bruckenkurs – text structure and dialogue

What is a unit of communication? M: hi. d4 to d6. J: uh–huh. (week passes) J: a3 to a7. M: hmmm. (2 weeks pass) M: Queen beats the laufer at e1. Check. ... Theories of discourse meaning depend in part on a specification of the basic units of a dicouse and the relations that can hold among them. Discourse processing requires an ability to determine to which portions of a discourse an individual utterance relates. Thus the role of discourse structure in discourse processing derives both from its role in delimiting units of discourse meaning and... bruckenkurs – text structure and dialogue

What is a discourse? “Assume that you have collected an arbitrary set of well-formed and independently interpretable utterances, for instance, by randomly selecting one sentence from each of the previous chapters of this book. Do you have a discourse? Almost certainly not. The reason is that these utterances, when juxtaposed, will not exhibit coherence. Consider, for example, the difference between passages (18.71) and (18.72).” (Jurafsky and Martin:695) • “Consider, for example, the difference between passages • (18.71) and (18.72). Assume that you have collected an arbitrary • set of well-formed and independently interpretable utterances, for • instance, by randomly selecting one sentence from each of the • previous chapters of this book.Almost certainly not. Do you have • a discourse?The reason is that these utterances,when • juxtaposed, will not exhibit coherence.” • vs…. “Assume that you have collected an arbitrary set of well-formed and independently interpretable utterances, for instance, by randomly selecting one sentence from each of the previous chapters of this book. Do you have a discourse? Almost certainly not~. The reason is that these utterances, when juxtaposed, will not exhibit coherence. Consider, for example, the difference between passages (18.71) and (18.72).” (Jurafsky and Martin:695) bruckenkurs – text structure and dialogue

The pool for members only. The pool for members only. Please use the toilet, not the pool. Please use the toilet, not the pool. What is a discourse? bruckenkurs – text structure and dialogue

What is a discourse? sentences are (typically) not processed in isolation discourse, unlike an arbitratry collection of utterances, forms an intentionally meaningful whole (discourses are „about” something) discourse has structure segmentation and ordering coherence cohesion bruckenkurs – text structure and dialogue

Discourse is internally linked; it „hangs together” • patterns oflexicalconnectivity cohesion • linguistic text-formingdevices: • lexical repetition, synonymy/antonymy, ellipsis/pro-forms, enumeration, parallelism, co-reference (anaphora) – Time flies. – You can’t; they fly too quickly. (Halliday and Hasan 1982) – Timeflies. – You can’t ~; theyfly too quickly. (Halliday and Hasan 1982) bruckenkurs – text structure and dialogue

Anaphora: pronominal My neighbor has a monster Harley 1200.They are huge but gas-efficient bikes. One should mind their own business. Anaphora: nominal (definite NP) Al bought a car the other day. […] He took it out of the garage last night with the helpof George Cottrell, and the thing gave forth such immense clouds of smoke that one man came running up and asked me where the fire was. […] I wanted a Trumpeter Swan who could play like Louis Armstrong, and I simply created him and named him Louis. The cutting of the webs between his toes is also fantastical, just as the bird itself is; […]. bruckenkurs – text structure and dialogue

Anaphora: surface-count and demonstrative Sarah could leave but she was also given an option to stay; she chose the latter. Have just driven to town, carrying our cook1 and our cook’s dog2. Gave the one1 $300 in currency and placed the other2 in the infirmary, with eczema. bruckenkurs – text structure and dialogue

Temporal anaphora If I must declare today that I am not a Communist, tomorrow I shall have to testify that I am not a Unitarian. And the day after, that I never belonged to a dahlia club. Spatial anaphora The awful hot spell broke last night and today is clear and beautiful, […] Across the street, the entire janitorial family has blossomed out in pink carnations, […] bruckenkurs – text structure and dialogue

Strained anaphora (bridging) John became a guitarist because he thought that it was a beautiful instrument. The house was beautiful. The door was painted white and the windows had blue shutters. bruckenkurs – text structure and dialogue

Abstract entity anaphora Each Fall, penguins migrate to Fiji. That’s where they wait out the winter. That’s when it’s cold even for them. That’s why I’m going there next month. It happens just before the eggs hutch. (Webber 1988) Send an engine to Elmira. That’s six hours. (Byron 2002) bruckenkurs – text structure and dialogue

Ellipsis The well water had chemicals in it and nothing in the house worked as it should [work]. [I] Have been uncommunicative lately, and [I have been] lagging in life’s race. I’m afraid my poem isn’t as nicely written as “Paradise Lost,” but anyway, it’s shorter[than “Paradise Lost”] . Ultimately, even after Garcia was gone, Ruelas was able to cope and move on with his career. And indeed, he has [coped and moved on with his career]. bruckenkurs – text structure and dialogue

To form the intended „whole” discourse segments can be • connected in a limited number of ways coherence • there exist linguistic devices that make structure explicit • identity(sameness): that is, that is to say, in other words, ... • opposition(contrast): but, yet, however, nevertheless, whereas, in contrast... • addition(continuation): and, too, also, furthermore, moreover, in addition,... • cause and effect: therefore, so, consequently, thus, it follows that, ... • concession (willingness to consider the other side): admittedly, true, I grant,... • exemplification(shift from general/abstract to specific/concrete idea): for example, for instance, after all, an illustration of, indeed, in fact, specifically,... • discourse comprehension consists of recognizing the structure bruckenkurs – text structure and dialogue

John went to his favourite music store to buy a piano. He was excited that he could finally buy a piano. John went to his favourite music store to buy a piano. He was excited that he could finally buy a piano. Coherence vs. Cohesion coherence: structural, functional relations between sentences cohesion:non-structural, text-forming relations that “tie” parts of discourse together bruckenkurs – text structure and dialogue

John went to his favourite music store to buy a piano. It was a store John had frequented for many years. He was excited that he could finally buy a piano. John went to his favourite music store to buy a piano. He had frequented the store for many years. He was excited that he could finally buy a piano. Coherence vs. Cohesion coherence: structural, functional relations between sentences cohesion:non-structural, text-forming relations that “tie” parts of discourse together bruckenkurs – text structure and dialogue

John went to his favourite music store to buy a piano. It was a storeJohn had frequented for many years. He was excited that he could finally buy a piano. John went to his favourite music store to buy a piano. He had frequented the store for many years. Hewas excited that he could finally buy a piano. Coherence vs. Cohesion coherence: structural, functional relations between sentences cohesion:non-structural, text-forming relations that “tie” parts of discourse together bruckenkurs – text structure and dialogue

John went to his favourite music store to buy a piano. It was a storeJohn had frequented for many years. He was excited that he could finally buy a piano. It was closing just as John arrived. John went to his favourite music store to buy a piano. He had frequented the store for many years. Hewas excited that he could finally buy a piano. He arrived just as the store was closing for the day. Coherence vs. Cohesion coherence: structural, functional relations between sentences cohesion:non-structural, text-forming relations that “tie” parts of discourse together bruckenkurs – text structure and dialogue

John went to his favourite music store to buy a piano. It was a storeJohn had frequented for many years. He was excited that he could finally buy a piano. It was closing just as John arrived. John went to his favourite music store to buy a piano. He had frequented the store for many years. Hewas excited that he could finally buy a piano. Hearrived just as the store was closing for the day. Coherence vs. Cohesion coherence: structural, functional relations between sentences cohesion:non-structural, text-forming relations that “tie” parts of discourse together bruckenkurs – text structure and dialogue

Coherence vs. Cohesion coherence: structural, functional relations between sentences cohesion:non-structural, text-forming relations that “tie” parts of discourse together When Teddy Kennedy paid a courtesy call on Ronald Reagan recently, he made only one Cabinet suggestion. Western surveillance satellites confirmed huge Soviet troop concentrations virtually encircling Poland. (Hobbs 1982) E: Forks have windows. P: Yes they do. Augmented pretension. Four plus four equals sixteen. It is a larger element, it’s photographic and phototrophic, but it is a higher number, higher course-work. It grows through evaporation or nocturnalism, it is sleepy, you rediscover it and I suppose forks could have windows through evaporation. bruckenkurs – text structure and dialogue

Discourse modeling: intentional approach • discourse participants have certain goals (agendas) to achieve • utterances : actions that realize the intentions • speaker’s plan wrt. communicating intentions ties the discourse • together • discourse understanding : recognizing speaker’s intentions bruckenkurs – text structure and dialogue

Intentional Approach (Grosz and Sidner 86) • three dimensions of discourse • linguistic structure : the utterances • intentional structure : hierarchy of intentions (communicative goals) • attentional structure : model of objects, properties and relations that are salient at each point in discourse • (dynamically changing) bruckenkurs – text structure and dialogue

Intentional Approach (Grosz and Sidner 86) • Linguistic structure • discourse segments + relations that hold between them bruckenkurs – text structure and dialogue

Intentional Approach (Grosz and Sidner 86) • Linguistic structure • discourse segments + relations that hold between them • (para-) linguistic expressions reflect discourse structure • cue phrases, aspect, tense, intonation, gesture • discourse structure constraints discourse interpretation • anaphora resolution bruckenkurs – text structure and dialogue

Intentional Approach (Grosz and Sidner 86) • Attentional structure • participants’ focus of attention (what is „attended to”) • modeled by focus spaces: objects and relations in focus • changes: insertion and deletion rules bruckenkurs – text structure and dialogue

Intentional Approach (Grosz and Sidner 86) • Intentional structure • Discourse Purpose (DP) • purpose/intention held by discourse initiator • e.g. make hearer: • intend to perform a task, • believe a fact, • believe that one fact supports another fact, • identify an object, • identify a property of an object • assumption: one per discourse bruckenkurs – text structure and dialogue

Intentional Approach (Grosz and Sidner 86) • Intentional structure • Discourse Segment Purpose (DSP) • how given segment contributes to DP bruckenkurs – text structure and dialogue

Intentional Approach (Grosz and Sidner 86) • Intentional structure • Hierarchy of intentions • dominance • DSP1 dominates DSP2 if satisfying DSP2 is intended to provide part of satisfaction of DSP1 • precedence • DSP1 precedes DSP2 if DSP1 must be satisfied before DSP2 bruckenkurs – text structure and dialogue

Discourse modeling: functional approach relations between discourse units relations may be made explicit by linguistic cues model: domain-independent rhetorical structure compositionally built discourse tree bruckenkurs – text structure and dialogue

Rhetorical Structure Theory (Mann and Thompson 87) nucleus(N) vs. satellite(S)segments core vs. peripheral part of the message „nuclearity principle” relations defined in terms of: constraints on the nucleus constraints on the satellite constraints on the comination of N and S effect achieved on the text receiver „classical RST”: 24 relations, (Mann, 2005): 30 relations bruckenkurs – text structure and dialogue

Rhetorical Structure Theory (Mann and Thompson 87) example relations Elaboration: set/member, class/instance/whole/part…Contrast: multinuclearCondition: S presents precondition for NPurpose: S presents goal of action in NSequence: multinuclearResult: N results from something presented in S bruckenkurs – text structure and dialogue

Rhetorical Structure Theory(Mann and Thompson 87) Evidence:S provides evidence for what N claims constraints on N: Reader might not believe N to a degree satisfactory to Writer on S: R believes S or will find it credible on N and S: R's comprehending S increases R's belief of N effect of W: R's belief of N is increased bruckenkurs – text structure and dialogue

Rhetorical Structure Theory (Mann and Thompson 87) Evidence:S provides evidence for what N claims constraints on N: Reader might not believe N to a degree satisfactory to Writer on S: R believes S or will find it credible on N and S: R's comprehending S increases R's belief of N effect of W: R's belief of N is increased [ George Bush supports Big Business. ]N [ He is sure to veto House Bill 1711. ]S bruckenkurs – text structure and dialogue

Rhetorical Structure Theory (Mann and Thompson 87) (volitional) Cause:S presents a cause that motivates N constraints on N: N is a volitional action or else a situation that could have arisen from a volitional action on N and S: S could have caused the agent of the volitional action in N to perform that action; without the presentation of S, R might not regard the action as motivated or know the particular motivation; N is more central to W's purposes than S. effect of W: R recognizes S as a cause for the volitional action in N bruckenkurs – text structure and dialogue

Rhetorical Structure Theory (Mann and Thompson 87) (volitional) Cause:S presents a cause that motivates N constraints on N: N is a volitional action or else a situation that could have arisen from a volitional action on N and S: S could have caused the agent of the volitional action in N to perform that action; without the presentation of S, R might not regard the action as motivated or know the particular motivation; N is more central to W's purposes than S. effect of W: R recognizes S as a cause for the volitional action in N [ George Bush supports Big Business. ]S [ He is sure to veto House Bill 1711. ]N bruckenkurs – text structure and dialogue

Problems with RST bruckenkurs – text structure and dialogue

Problems with RST (cf. Moore and Pollack 92) how many Rhetorical Relations are there? how can we use RST in dialogue as well as monologue? how to incorporate speaker’s intentions into RST? RST does not allow for multiple relations holding between parts of a discourse RST does not model overall structure of the discourse bruckenkurs – text structure and dialogue

Computation of discourse coherence grammar-basedanalogous to sentence grammar: encode RRs as rules, parse (Polanyi) inference-basedproof-system: encode RRs as axioms, prove coherence, e.g. by abduction (Hobbs et al.) plan-basedencode RRs as plan operators, instantiate plan given disourse goal (Litman&Allen) shallow rules:schemata/templates, lexical clues (Marcu) bruckenkurs – text structure and dialogue

Automatic identification of rhetorical structure (Marcu 99 and later work) parser trained on a discourse treebank • 90 hand-annotated rhetorical structure trees • Elementary Discourse Units (EDU) linked by Rhetorical Relations (RR) • parser learns to identify N and S and their RR • mainly shallow features: lexical, structural, Wordnet-based similarity discourse segmenter (toidentify EDUs) • trained to segment on hand-labeled corpus (C4.5) • mainly shallow features: 5-word POS window, presence of discourse markers, punctuation, presence/absence of particular syntactic items • 96-8% accuracy bruckenkurs – text structure and dialogue

Automatic identification of rhetorical structure (Marcu 99 and later work) evaluation of Marcu’s parser  hierarchical structure easier to identify than rhetorical structure bruckenkurs – text structure and dialogue

Dialog bruckenkurs – text structure and dialogue

Dialog linguistic properties (cohesive devices) structure manifested in the dialog partys’ contributions speech-related phenomena: pauses and fillers („uh”, „um”, „..., like, you know,...”) prosody, articulation disfluencies overlapping speech spontaneous vs. „practical” dialogs topic drifts vs. goal-orientedness bruckenkurs – text structure and dialogue

Dialog dialog is made up of turns speaker A says sth, then speaker B, then A... how do speakers know when it’s time to contribute a turn? there are points in dialog/utterance structure that allow for a speaker shift Transition-Relevance Points (TRP) e.g. intonational phrase boundaries bruckenkurs – text structure and dialogue

Dialog dialog is made up of turns speaker A says sth, then speaker B, then A... turn taking rules determine who is expected to speak next at each TRP of each turn: if current speaker has selected A as next speaker, then A must speaknext if current speaker does not select next speaker, any other speaker may take next turn if no one else takes next turn, the current speaker may take next turn bruckenkurs – text structure and dialogue

Dialog some turns specifically select who the next speaker will be adjacency pairs regularly occuring, conventionalized sequences conventions introduce obligations to respond (and preferred responses) greeting :greeting question : answer complement : downplayer accusation : denial offer : acceptance request : grant set up next speaker expectations (‘significant silence’ dispreferred) bruckenkurs – text structure and dialogue

Dialog entering a conversation we (typically) have a certain intention paradigmatic use of language: making statements... ...BUT there are also other things we can do with words e.g. make requests, ask questions, give orders, make promises, give thanks, offer apologies aspects of the speaker's intention: the act of saying something, what one does in saying it (requesting or promising) how one is trying to affect the audience bruckenkurs – text structure and dialogue

Dialog: speech acts certain actions we take in communication are designed to get our interlocutor(s) to do things on the basis of understanding of what we mean doing things with words: Austin, 1962, later Searle, Davis  speech acts utterances are multi-dimentional acts that affect the context in which theyare spoken bruckenkurs – text structure and dialogue

Dialog: speech acts dimensions locutionary act: uttering something with a certain „meaning” illocutionary act: act performed by means of uttering the words  utterance’s „conventional force” perlocutionary act: what is brought about as a result (intentionally or not)  how hearer is affected: convincing the hearer, persuading, surprising, making sad, laugh, etc. bruckenkurs – text structure and dialogue

Dialog: speech acts examples of illocutionary acts assertive: get H to form or attend to a belief; e.g. „claim” „conclude” directive: get H to do sth; e.g. „order”, „request”, „beg” commissive: S commits to doing sth; e.g. „promise”, „plan”, „vow”, „bet” expressive: S expresses a psychological state, feeling twrd. H „thank”, „apologize”, „hate”, „love” declarations: S changes the state of the world; e.g. „resign”, „fire”, „name”, „baptize”, „pronounce husband and wife” bruckenkurs – text structure and dialogue

discourse and dialogue