Finding the sources and targets of subjective expressions

1. Finding the sources and targets of subjective expressions Josef Ruppenhofer, Swapna Somasundaran, Janyce WiebeUniversity of Pittsburgh

2. What is Subjectivity? • The linguisticexpression of somebody’s opinions, sentiments, emotions, evaluations, beliefs, speculations (private states) • Thispleasedthe mainly female audience. • Source: the person who experiences a private state • Target: what the private state is about or directed towards

3. Motivation Sentiment analysis is a fast-growing field with many applications (e.g. Question Answering, Product review mining, Information Extraction) In many kinds of texts we find opinions attributed to several different sources, and/or opinions about multiple targets

4. Opinion Question Answering Q: What is the international reaction to the reelection of Robert Mugabe as President of Zimbabwe? A: African observers generally approved of his victory while Western Governments stronglydenounced it.

5. Product review mining The computer is very good and very easy to use. It has a built in camera, bluetooth; the all singing and dancing machine. Love it. The only glitch is the scrolling pad is not as smooth as my last Toshiba notebook. One other thing is that Vista is a nightmare...

6. Motivation Sentiment analysis is a fast-growing field with many applications (e.g. Question Answering, Product review mining, Information Extraction) In many kinds of texts we find opinions attributed to several different sources, and/or opinions about multiple targets Challenge is to associate sources, opinions, and targets correctly

7. Roadmap • Here we discuss some of the challenges that an automatic system needs to be able to deal with • We take the use of Automatic Semantic Role Labeling (ASRL) systems as our starting point • Based on our work in corpus annotation, we show that we need additional capabilities beyond ASRL

8. Automatic Semantic Role Labeling

9. Semantic roles • Thispleasedthe mainly female audience. • Wefearan early death much more.

10. Mapping opinion roles to semantic roles • Thispleasedthe mainly female audience. • Wefearan early death much more.

11. Annotation scheme

12. Private states (Quirk et al. 1985) • States such as emotions, evaluations, speculations, etc. • States that are not open to objective observation or verification. • States that involve a particular person’s point of view • Private states involve sources holding attitudes, typically towards targets.

13. Ways of evoking private states DSEs ESEs Explicit mentions:He was boiling with anger. Speaking events expressing private states:The paper’s editors attacked the new House Speaker. Expressive subjective elements (Banfield 1982):That doctor is a quack. Objective speech events:“The bus leaves at 4”, Bill said.

14. Nesting of private states ``The US fears a spill-over,” said Xirao-Nima.

15. Nesting of private states ``The US fears a spill-over,” said Xirao-Nima. <writer> “ “ said Xirao-Nima The US fears a spill-over

16. Challenges beyond role labeling

17. Attribution

18. Attribution Expressive subjective elements (ESEs) don’t have a semantic role for their source:Senior Mike Sheehy said , “It was a blast ”.

19. Attribution The source for an ESE is not always at the same level. Compare:Senior Mike Sheehy said, “It was a blast”. She loves that idiot.

20. <writer> <writer> Senior Mike Sheey said, “It was a blast” She loves that idiot.

21. Attribution Some expressions function both as ESEs and as DSEs:

22. Attribution Some expressions function both as ESEs and as DSEs:It is a shame that there is no jury that can mete out justice for a city he has slandered for far too long.

23. Attribution Attribution and content of a private state may be presented separately:

24. Attribution Attribution and content of a private state may be presented separately: Chris Moyles is a brilliant broadcaster, the saviour of Radio 1, a comedian, a best-selling author, and, in fact, a genius. Or so he says.

25. Attribution <writer> Chris Moyles is a brilliant broadcaster, the saviour of Radio 1, a comedian, a best-selling author, and, in fact, a genius.

26. Attribution <writer> <Chris Moyles> Chris Moyles is a brilliant broadcaster, the saviour of Radio 1, a comedian, a best-selling author, and, in fact, a genius. Or so he says

27. Attribution And I went ahead and mailed it in thinking uh I won’t get the scholarship. Who cares? I don’t, just so I can work in the school and I’ll be happy. But one day I came in and I looked at my mail and I was accepted. An attribution may apply to several utterances without being explicitly signaled each time.

28. Inferences

29. Inferences For some events about which opinions are expressed, we can infer additional attitudes towards affected or causing participants:

30. Inferences For some events about which opinions are expressed, we can infer additional attitudes towards affected or causing participants:I think people are happybecause Chavez has fallen.

31. Inferences For some events about which opinions are expressed, we can infer additional attitudes towards affected or causing participants:I think people are happybecause Chavez has fallen. I think people are happy because Chavez has fallen.

32. Targets of arguing

33. Arguing attitudes • What is the case or not From this it follows that mechanisation is not economic unless it can produce higher yields of crops than these older methods. • What should be done or not We strongly recommend that all Firefox users upgrade to this latest release.

34. Targets of arguing Interpretation of arguments made by causal and conditional constructions is very context-dependent. Your presentation will be better [ifyouput this on the first slide] You will want to vote YES [if you want to keep the cost of government in Lewiston low]

35. Targets of arguing Interpretation of arguments made by causal and conditional constructions is very context-dependent. Hypothetical: Your presentation will be better [ifyouput this on the first slide] Implicit assertion You will want to vote YES [if you want to keep the cost of government in Lewiston low]

36. Targets of arguing • The prototypical targets that we annotate are entities. • For arguing, we could also annotate the entities that arguments are about. • However, we also recognize that the logical targets of arguing are propositions.

37. Targets of arguing • Clinton should be the presidential candidate. Clinton should be the running mate. • The prototypical targets that we annotate are entities. • For arguing, we could also annotate the entities that arguments are about. • However, we also recognize that the logical targets of arguing are propositions.

38. Targets of arguing • Clintonshould be the presidential candidate. Clintonshould be the running mate. • The prototypical targets that we annotate are entities. • For arguing, we could also annotate the entities that arguments are about. • However, we also recognize that the logical targets of arguing are propositions.

39. Targets of arguing • Clinton should be the presidential candidate. Clinton should be the running mate. • The prototypical targets that we annotate are entities. • For arguing, we could also annotate the entities that arguments are about. • However, we also recognize that the logical targets of arguing are propositions.

40. Targets of arguing • Clintonshould be the presidential candidate. Clintonshould be the running mate. • The prototypical targets that we annotate are entities. • For arguing, we could also annotate the entities that arguments are about. • However, we also recognize that the logical targets of arguing are propositions.

41. Conclusion • Semantic role labeling is needed for finding sources and targets • But we also need • ways of establishing levels of attribution • capabilities for dealing with zero references • lexical information to support inferences • deal with the full variety of attitudes and their sources and targets

42. Thanks!josefr@cs.pitt.edu

43. References: Annotation scheme • Banfield, Ann. 1982. Unspeakable Sentences: Narration and Representation in the Language of Fiction. Routledge & Kegan Paul, Boston. • Quirk Randolph, Greenbaum Sidney, Leech Geoffrey, and Svartvik Jan. 1985. A Comprehensive Grammar of the English Language. Longman, New York, NY. • Janyce Wiebe M. 1994. Tracking point of view in narrative. Computational Linguistics 20 (2): 233-287.

44. References: Annotation scheme • Janyce Wiebe, Theresa Wilson , and Claire Cardie. 2005. Annotating expressions of opinions and emotions in language. Language Resources and Evaluation, volume 39, issue 2-3, pp. 165-210.

45. References: Role Labeling • Penn Discourse Treebank http://www.seas.upenn.edu/~pdtb/PDTBAPI/pdtb-annotation-manual.pdf • PropBankhttp://verbs.colorado.edu/~mpalmer/projects/ace.html • FrameNethttp://framenet.icsi.berkeley.edu/

46. References: Role Labeling • Y. Choi, E. Breck, and C. Cardie. 2006. Joint Extraction of Entities and Relations for Opinion Recognition. In Proc. of EMNLP 2006. • S. Kim and E. Hovy. 2006. Extracting Opinions, Opinion Holders, and Topics Expressed in Online News Media Text. In ACL Workshop on Sentiment and Subjectivity in Text.

47. References: Belief spaces • Dyer, Michael G. 1983. In-Depth Understanding: A Computer Model of Integrated Processing for Narrative Comprehension. MIT Press, Cambridge, MA. • Fauconnier, Gilles. 1985. Mental Spaces: Aspects of Meaning Construction in Natural Language. MIT Press, Cambridge, MA.

48. References: Belief spaces • Rapaport, William J. 1986. Logical Foundations for Belief Representation. Cognitive Science. • Wilks, Yorick and Bien, Janusz. Beliefs, Points of View, and Multiple Environments. Cognitive Science 7: 95-119.

49. References: Literary theory • Chatman, Seymour. 1978. Story and Discourse: Narrative Structure in Fiction and Film. Cornell University Press, Ithaca, NY. • Cohn, Dorrit. 1978. Transparent Minds: Narrative Modes for Representing Consciousness in Fiction Princeton University Press, Princeton, NJ. • Dolezel, Lubomir. 1973 .Narrative Modes in Czech Literature. University of Toronto Press, Toronto, Canada.

50. References: Literary theory • Hamburger Käte. 1973. M.J. Rose, Trans., The Logic of Literature. Indiana University Press, Bloomington, Indiana. • Kuroda, S.-Y. 1976. Reflections on the Foundations of Narrative Theory--From a Linguistic Point of View. In: van Dijk, T.A., Ed., Pragmatics of Language and Literature, North Holland, Amsterdam. • Uspensky, Boris. 1973. A Poetics of Composition. University of California Press, Berkeley, CA.