Att ventilera en (pragmatik-) uppsats

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1 Att ventilera en (pragmatik-) uppsats Pragmatik VT06 Ventilering (20-30 minuter) 1. Respondenten (författaren) berättar om sistaminuten-ändringar. 2. Opponenten presenterar uppsatsen. 3. Respondenten kompletterar presentationen. 4. Opponenten ställer kritiska frågor, som respondenten besvarar efter bästa förmåga. 5. Auditoriet (åhörarna) ställer frågor. 1 2 Presentation av uppsatsen! Lyft fram huvuddragen! Presentera så att någon som inte läst uppsatsen kan förstå vad den handlar om! Om lämpligt, visa exempel för att öka åhörarnas förståelse! Använd oh, ppt, skriv på tavlan..! Ha inte med någon värdering här, dvs säg inte vad du tycker är bra eller dåligt 3 Att läsa en uppsats kritiskt! Exempel på frågor att titta på: " Knyter avslutningen an till inledningen? Dvs, gör författaren det hon säger sig göra? " Vilken metod använder författaren? Är den lämplig? " Ger uppsatsen de resultat som författaren påstår? " Saknas något? Är något onödigt? 4 Att ställa kritiska frågor till respondenten! Koncentrera dig på innehållet, inte formen " Dvs ta inte upp stavfel och liknande! Utgå ifrån de saker du fann under din kritiska läsning av uppsatsen! Ställ gärna frågor om sådant du tyckte var oklart! Ha gärna med positiva saker med uppsatsen Praktiskt! Före 23 mars kommer opponenter och respondenter att paras ihop, och ett schema kommer läggas ut! Opponenten behöver få uppsatsen några dagar före ventileringen 5 6

2 A pragmatic issue Centering Theory Pragmatik VT06! Just how are pronouns and descriptive NPs interpreted (resolved) in a discourse? 7 8 An example Centering theory (1) Jane likes Mary. (2) She often brings her flowers. (3) She chats with the young woman for ages! Centering a key element of local discourse coherence " A system of rules and constraints that govern:! the relationship between what the discourse is about and some of the linguistic choices made by discourse participants! choice of syntactic structure! type of referring expression (proper noun, definite or indefinite description, reflexive or personal pronoun, etc) (Brennan, Friedman & Pollard 1987) 9 10 Centering theory! Attempts to characterise the texts that can be considered coherent on the basis of the way discourse entities are introduced and discussed! Attempts to predict which entities will be most salient at any given time (Poesio et al 2000) Main themes (1)! Discourse is viewed dynamically " A sentence/utterance is a transition from an input state to an output state! The state " determines which entities are under discussion: the centers of attention " represents the utterance s anaphoric potential " captures the relative salience of various discourse entities 11 12

3 Main themes (2) The Centering model! The transitions (between states) are classified according to amount of change involved " Transitions involving only little change: coherent discourse " Transitions involving much change: incoherent discourse Backward-looking center (CB) Forward-looking center (CF)! A state comprises a backward-looking center and a forward-looking center list! A backward-looking center (CB)! A discourse referent! A link to the previous sentence! The most significant entity under discussion in both the current and previous sentence! CB(Un): the bw-looking center of the nth utterance! A forward-looking center list (CF) " A list of discourse referents! CF(Un): a list of all the referents in utterance n " Ordered according to salience (= grammatical obliqueness) 1. The subject: first element, most salient (least oblique) Is also the preferred center (PF) 2. Direct object 3. Indirect object 4. Adjuncts: last elements, least salient (most oblique) The algorithm (1) The algorithm (2) 1. CONSTRUCT " The alternative possibilities for anaphoric resolution are identified " Each possibility maps pronouns in the sentence to discoure entities, respecting agreement features " For each possibility:! CF(Un) consists of all the referents of NPs in the sentence! CB(Un) is chosen from CF(Un-1) or NIL 2. FILTER Possibilities are discarded unless all of the following criteria are met: 1. If there are pronouns in the current sentence, then one of them is the bw-looking center of the current sentence (the Rule 1 ) 2. The bw-loooking center is mapped onto the entity mentioned in the current sentence which is highest ranked in the previous sentence s fwdlooking center 3. Syntactic coreference constraints are upheld 17 18

4 The algorithm (3) The algorithm (4) 3. CLASSIFY 4. SELECT Classify each possibility as one of the transition types: " continue " retain " smooth shift " rough shift Chose the best possibility, using the ranking over transition types: continue > retain > smooth shift > rough shift > = is preferred over Transition types (1) Transition types (2)! State transitions are classified according to amount of change involved: " Continue:! Bw-looking center is unchanged, i.e CB(Un-1) = CB(Un)! Bw-looking center is also preferred center in the new utterance, i.e CB(Un) = CP(Un) " Retain:! Bw-looking center is unchanged, i.e CB(Un-1) = CB(Un)! Bw-looking center is no longer in preferred position, i.e CB(Un)! CP(Un) Transition types (3) Transition types (3) " Smooth shift:! New bw-looking center is different from old, i.e CB(Un-1)! CB(Un)! Bw-looking center is the same as the preferred center, i.e CB(Un) = CP(Un) " Rough shift:! New bw-looking center is different from old, i.e CB(Un-1)! CB(Un)! Bw-looking center is no longer in preferred position, i.e CB(Un)! CP(Un) 23 24

5 Consider the following discourse again: Sentence (1): Jane likes Mary. (1) Jane likes Mary. (2) She often brings her flowers. (3) She chats with the young woman for ages Question: What do the pronouns and the definite description (underlined) refer to? 1. Construct: CF(U1): <Jane, Mary> CB(U1): NIL CP(U1): Jane 2. Filter: x 3. Classify: - 4. Select: Construct: CF(U2): <Jane, Mary, flowers> or <Mary, Jane, flowers> or <Jane, Jane, flowers> or <Mary, Mary, flowers> CB(U2): Jane or Mary CP(U2): Jane or Mary 2. Filter: By (1): she or her refers to CB By (2): CB(U2) is Jane By (3): <Jane, Jane, flowers> & <Mary, Mary, flowers> are ruled out Classify: (a) CF(U2): <Jane, Mary, flowers> CB(U2): Jane CP(U2): Jane So, CB(U2)! CB(U1), CB(U2) = CP(U2) i.e smooth shift (b) CF(U2): <Mary, Jane, flowers> CB(U2): Jane CP(U2): Mary So, CB(U2)! CB(U1), CB(U2)! CP(U2) i.e rough shift 4. Select: smooth shift 29 30

6 So CT predicts: (1) Jane likes Mary (2) She often brings her flowers = Jane often brings Mary flowers 1. Construct: CF(U3): <Jane, Mary> or <Mary, Jane> or <Jane, Jane> or <Mary, Mary> CB(U3): Jane or Mary or flowers or NIL CP(U3): Jane or Mary Filter: By (1): CB(U3) is Jane or Mary By (2): CB(U3) is Jane By (3): <Jane, Jane> & <Mary, Mary> are ruled out Classify: (a) CF(U3): <Jane, Mary> CB(U3): Jane CP(U3): Jane So, CB(U3) = CB(U2), CB(U3) = CP(U3) i.e continue (b) CF(U3): <Mary, Jane> CB(U3): Jane CP(U3): Mary So, CB(U3) = CB(U2), CB(U3)! CP(U3) i.e retain 34 So: 4. Select: continue (1) Jane likes Mary (2) She often brings her flowers = Jane often brings Mary flowers (3) She chats with the young woman for ages = Jane chats with Mary for ages 35 36

7 Poesio et al: Specifying the Parameters of Centering Theory: a Corpus-Based Evaluation using Text from Application-Oriented Domains Poesio et al! CT is a parametric theory! There are different versions of CT " They give different values to different parameters! Examples of parameters & values: " Should utterance be a full sentence, or a clause, or..? " What counts as the realisation of a reference? Only direct (Jane.. She..) or also via bridging (The painting.. The frame..)?! And how does it work for different languages? Poesio et al! First goal: " Which values for the parameters would make the claims of CT most accurate?! Second goal: " Evaluate CT predictions in domains of interest for real applications: corpora of instructional texts and descriptions of museum objects Poesio et al! First goal involves automatic check of two central CT claims: " Constraint 1: All utterances of a segment except for the first have exactly one CB " Rule 1: If any discourse referent is pronominalised, the CB is! Another claim that can be checked: " Rule 2: continue > retain > shift Literature Övning för Centering Theory! David Beaver The Optimization of Discourse Anaphora. Linguistics and Philosophy 27(1), pp " First 10 pages are a good introduction to Centering Theory " Massimo Poesio et al Specifying the Parameters of Centering Theory: a Corpus-Based Evaluation using Text from Application-Oriented Domains. Proceedings of the 38th ACL. " S E Brennan, M W Friedman & C J Pollard A Centering Approach to Pronouns. Proceedings of the 25th ACL. " Se schemat! Inlämning onsdag 8 mars 41 42