Sentence Processing III

1. Sentence Processing III BCS 261 4/13/04

2. DO/SC Ambiguity Preferred The historian read [ the manuscript ]DO during the trip. Dis-preferred The historian read [ the manuscript had been destroyed in the fire]SC. The garden path models predicts that the preferred analysis gets computed in all context initially.

3. Constraint Based View Two other types of information are used to resolve an ambiguity. What are they?

4. Verb Bias The proportion of time the verb occurs with a given syntactic frame: Admitted (SC Bias) John admitted he was wrong (60%) John admitted the error (9%) Accepted (DO Bias) John accepted that he was wrong (1%) John accepted the money (98%) Announced (Equibiased) John announced that he won the lottery (48%) John announced the good news (49%)

5. Verb Bias Predictions: Listeners have to track frequency. How could we investigate whether and how listeners do this?

6. Plausibility How plausible a given interpretation is: DO bias The talented photographer accepted… . . .the money could have been spent. . . .the fire could have been prevented. SC Bias The factory owner suspected… . . .the cash would probably not last long. . . .the workers would probably go on strike.

7. Constraint Based and Garden Path Theories • Both types of theories predict difficulty for the following: Preferred The historian read [ the manuscript ]DO during the trip. Dis-preferred The historian read [ the manuscript had been destroyed in the fire]SC. But make different predictions for this sentence: (1) The bus driver worried the tires were starting to go flat

8. Goal of Garnsey paper • Constraint Based Model Does plausibility play an early role? Does verb bias (frequency)? Lexical filtering vs. lexical guidance • Methodology Are similar results obtained in eye-tracking and moving window studies?

9. Plausibility Lots of studies are discussed, all with inconsistent results regarding plausibility and frequency… Why the varied results?

10. Operationalizing plausibility and frequency • How do Garnsey it al. measure plausibility and frequency?

11. Plausibility and Bias Garnsey et al. hypothesize that both verb bias and plausibility have a role but verb bias will be a more influential factor. Why?

12. Analogy to words Duffy, Morris, and Rayner (1988) Biased words - Context does not eliminate frequency of the most frequent meaning. Ex. John likes to drink after a meal and often enjoys a glass of port. (drink, dock) Equibiased words - Context does eliminate frequency effects. Ex. Baseball fans often love their teams pitcher. (batter, container) Rayner et al. want to argue syntactic information is contained in words (MacDonald, Pearlmutter, & Seidenberg, 1994), so frequency and plausibility should behave as they do in lexical disambiguation.

13. Theory Plausibilty and verb bias both play a role. Verb bias is stronger. Plausibility will not affect biased verbs (DO difficult, SC easy). Plausibility will affect equibiased word.

14. Ambiguity Effects Garnsey et al look at ambiguity effects: Ambiguous sentence RT - Unambiguous sentence RT = Ambiguity effect Ambiguous The senator regretted the decision had ever been made public. 379 ms Unambiguous The senator regretted that the decision had ever been made public. 338ms 379ms - 338ms = 41ms Effect

15. Conditions DO Bias The senior senator regretted (that) the decision had ever been made public. (plausible) The senior senator regretted (that) the reporter had ever seen the report (implausible). Equibiased The sales clerk acknowledged (that) the error should have been detected earlier. (plausible) The sales clerk acknowledged (that) the shirt should have been marked down. (implausible) SC Bias The ticket agent admitted (that) the mistake had been careless and stupid. (plausible) The ticket agent admitted (that) the airplane had been late taking off. (implausible)

16. Results Garnsey et al. point out that a garden path theory can explain the results. Why?

17. More Results Why are these results problematic for a garden path theory?

18. Correlations • The factor that most consistently influenced difficulty at disambiguation point was verb bias. • Verb bias’ influence on difficulty was only significant when plausibility supported the verb’s less frequent structure. (when the two factors conflicted).

19. More Correlations When SC-bias verbs were followed by NPs that were plausible as direct objects, difficulty was correlated with the verbs’ DO-bias Ex. The ticket agent admitted the mistake had been careless and stupid… How is this finding problematic for their theory? Does it fit with a garden path model?

20. Papers Grades 2nd draft can replace score of 1st draft. Both groups need to schedule a time to meet with me.

21. Papers • Intro should say what you’re studying…don’t jump straight into the literature review. • Don’t wait until method section to discuss the experiment • How do the theoretical predictions translate into concrete results?

22. Ferreira & Henderson (1990) In an eye-tracking study, F&H found no effects of verb bias on first fixation durations. Ed disputed eggs caused heart problems. Ed asserted eggs caused heart problems. What were some of the criticisms of this experiment? NP verb disambiguation point

23. Trueswell et al (1993) • Conducted a study with strongly biased stimuli, and nouns that were plausible direct objects of the DO bias verbs. • Slower reading times at disambiguation point for DO bias verbs than SC-bias verbs. • Mr. Smith remembered the directions were confusing. • Mr Smith claimed the directions were confusing. More slow down on the SC biased NP. Why is this problematic for demonstrating early verb bias effects?

24. Trueswell (cont’d) The slow downs on the SC biased NPs was due to the complexity of processing a SC. They argue that “that” bias predicted slow downs and that it suggests that verb specific information was coming in to rapidly to support the filtering hypothesis. Tanenhaus found that “that” was a poor predictor, but verb familiarity was a better one. What analogy is drawn between processing sentences and words? (p.63)