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CS3730 Fall 2008 Subjectivity and Sentiment Analysis

CS3730 Fall 2008 Subjectivity and Sentiment Analysis. Lecture (Day 2): Introduction to linguistic subjectivity. Definitions and Annotation Scheme. Manual annotation: human markup of corpora (bodies of text) Why? Understand the problem Create gold standards (and training data)

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CS3730 Fall 2008 Subjectivity and Sentiment Analysis

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  1. CS3730 Fall 2008Subjectivity and Sentiment Analysis Lecture (Day 2): Introduction to linguistic subjectivity

  2. Definitions and Annotation Scheme • Manual annotation: human markup of corpora (bodies of text) • Why? • Understand the problem • Create gold standards (and training data) Wiebe, Wilson, Cardie LRE 2005 Wilson & Wiebe ACL-2005 workshop Somasundaran, Wiebe, Hoffmann, Litman ACL-2006 workshop Somasundaran, Ruppenhofer, Wiebe SIGdial 2007 Wilson 2008 PhD dissertation

  3. What is Subjectivity? • The linguisticexpression of somebody’s opinions, sentiments, emotions, evaluations, beliefs, speculations (private states) Private state: state that is not open to objective observation or verification Quirk, Greenbaum, Leech, Svartvik (1985). A Comprehensive Grammar of the English Language.

  4. Overview • Fine-grained: expression-level rather than sentence or document level • Annotate • Subjective expressions • material attributed to a source, but presented objectively

  5. Overview • Focus on three ways private states are expressed in language

  6. Direct Subjective Expressions • Direct mentions of private states The United Statesfears a spill-over from the anti-terrorist campaign. • Private states expressed in speech events “We foresaw electoral fraud but not daylight robbery,” Tsvangirai said.

  7. Expressive Subjective Elements [Banfield 1982] • “We foresaw electoral fraud but not daylight robbery,” Tsvangirai said • The part of the US human rights report about China is full of absurdities and fabrications

  8. Objective Speech Events • Material attributed to a source, but presented as objective fact The government, it added, has amended the Pakistan Citizenship Act 10 of 1951 to enable women of Pakistani descent to claim Pakistani nationality for their children born to foreign husbands.

  9. Nested Sources “The report is full of absurdities,’’ Xirao-Nima said the next day.

  10. “The report is full of absurdities,’’ Xirao-Nima said the next day. Nested Sources (Writer)

  11. “The report is full of absurdities,’’ Xirao-Nima said the next day. Nested Sources (Writer, Xirao-Nima)

  12. “The report is full of absurdities,’’ Xirao-Nima said the next day. Nested Sources (Writer Xirao-Nima) (Writer Xirao-Nima)

  13. “The report is full of absurdities,’’ Xirao-Nima said the next day. Nested Sources (Writer) (Writer Xirao-Nima) (Writer Xirao-Nima)

  14. “The report is full of absurdities,” Xirao-Nima said the next day. Objective speech event anchor:the entire sentence source: <writer> implicit: true Direct subjective anchor:said source: <writer, Xirao-Nima> intensity: high expression intensity: neutral … Expressive subjective element anchor:full of absurdities source: <writer, Xirao-Nima> intensity: high …

  15. “The US fears a spill-over’’, said Xirao-Nima, a professor of foreign affairs at the Central University for Nationalities.

  16. (Writer) “The US fears a spill-over’’, said Xirao-Nima, a professor of foreign affairs at the Central University for Nationalities.

  17. (writer, Xirao-Nima) “The US fears a spill-over’’, said Xirao-Nima, a professor of foreign affairs at the Central University for Nationalities.

  18. (writer, Xirao-Nima, US) “The US fears a spill-over’’, said Xirao-Nima, a professor of foreign affairs at the Central University for Nationalities.

  19. (Writer) (writer, Xirao-Nima, US) (writer, Xirao-Nima) “The US fears a spill-over’’, said Xirao-Nima, a professor of foreign affairs at the Central University for Nationalities.

  20. “The US fears a spill-over’’, said Xirao-Nima, a professor of foreign affairs at the Central University for Nationalities. Objective speech event anchor:the entire sentence source: <writer> implicit: true Objective speech event anchor:said source: <writer, Xirao-Nima> Direct subjective anchor:fears source: <writer, Xirao-Nima, US> intensity: medium expression intensity:medium …

  21. The report has been strongly criticized and condemned by many countries.

  22. The report has been strongly criticized and condemned by many countries. Objective speech event anchor:the entire sentence source: <writer> implicit: true Direct subjective anchor:strongly criticized and condemned source: <writer, many-countries> intensity: high expressionintensity:high …

  23. As usual, the US state Department published its annual report on human rights practices in world countries last Monday. And as usual, the portion about China contains little truth and many absurdities, exaggerations and fabrications.

  24. As usual, the US state Department published its annual report on human rights practices in world countries last Monday. And as usual, the portion about China contains little truth and many absurdities, exaggerations and fabrications. Expressive subjective element anchor :And as usual source : <writer> intensity : low … Objective speech event anchor :the entire 1st sentence source : <writer> implicit : true Expressive subjective element anchor :little truth source : <writer> intensity : medium … Direct subjective anchor :the entire 2nd sentence source : <writer> implicit :true intensity : high … Expressive subjective element anchor :many absurdities, exaggerations, and fabrications source : <writer> intensity : medium …

  25. Example The Foreign Ministry said Thursday that it was “surprised, to put it mildly” by the U.S. State Department’s criticism of Russia’s human rights record and objected in particular to the “odious” section on Chechnya.

  26. (writer,FM) (writer,FM,FM) (writer,FM) (writer,FM,FM,SD) (writer,FM) (writer,FM) Example The Foreign Ministry said Thursday that it was “surprised, to put it mildly” by the U.S. State Department’s criticism of Russia’s human rights record and objected in particular to the “odious” section on Chechnya.

  27. (General) Subjectivity Types[Wilson 2008] Other (including cognitive) Note: similar ideas: polarity, semantic orientation, sentiment

  28. Extensions[Wilson 2008] I think people are happy because Chavez has fallen. direct subjective span: think source: <writer, I> attitude: direct subjective span: are happy source: <writer, I, People> attitude: inferred attitude span: are happy because Chavez has fallen type: neg sentiment intensity: medium target: attitude span: think type: positive arguing intensity: medium target: attitude span: are happy type: pos sentiment intensity: medium target: target span: people are happy because Chavez has fallen target span: Chavez has fallen target span: Chavez

  29. As usual, the US State Department published its annual report on human rights practices in world countries last Monday. GATE_objective-speech-event (2, 2) nested-source=w implicit=true [] GATE_agent (46, 108) id=report ['its', 'annual', 'report', 'on', 'human', 'right', 'practice', 'in', 'world', 'country'] And as usual, the portion about China contains little truth and many absurdities, exaggerations and fabrications. GATE_expressive-subjectivity (128, 140) nested-source=w polarity=neutral intensity=low ['and', 'as', 'usual'] GATE_direct-subjective (128, 128) nested-source=w attitude-link=a100 intensity=high implicit=true [] GATE_target (142, 165) id=t100 ['the', 'portion', 'about', 'china'] GATE_agent (160, 165) id=china ['china'] GATE_attitude (166, 240) intensity=high id=a100 attitude-type=sentiment-neg target-link=t100 ['contain', 'little', 'truth', 'and', 'many', 'absurdity', 'exaggeration', 'and', 'fabrication'] GATE_expressive-subjectivity (175, 187) nested-source=w polarity=negative intensity=medium ['little', 'truth'] GATE_expressive-subjectivity (192, 240) nested-source=w polarity=negative intensity=high ['many', 'absurdity', 'exaggeration', 'and', 'fabrication']

  30. Its aim of the 2001 report is to tarnish China's image and exert political pressure on the Chinese Government, human rights experts said at a seminar held by the China Society for Study of Human Rights (CSSHR) on Friday. GATE_objective-speech-event (248, 248) nested-source=w implicit=true [] GATE_direct-subjective (380, 384) nested-source=w,experts expression-intensity=neutral attitude-link=a110 intensity=medium ['say'] GATE_attitude (248, 357) intensity=medium-high id=a110 attitude-type=sentiment-neg target-link=t2 ['its', 'aim', 'of', 'the', 'report', … 'the', 'chinese', 'government'] GATE_target (259, 274) id=t2 ['the', 'report'] GATE_expressive-subjectivity (281, 288) nested-source=w,experts polarity=negative intensity=medium ['tarnish'] GATE_direct-subjective (252, 255) nested-source=w,experts,report polarity=neutral expression-intensity=medium attitude-link=a120,a130intensity=medium ['aim'] GATE_attitude (252, 255) intensity=medium id=a120attitude-type=intention-pos target-link=t3 ['aim'] GATE_target (278, 357) id=t3 ['to', 'tarnish', 'china', "'s", 'image', 'and', 'exert', 'political', 'pressure', 'on', 'the', 'chinese', 'government'] GATE_attitude (252, 288) intensity=medium id=a130attitude-type=sentiment-neg target-link=t4 ['aim', 'of', 'the', 'report', 'be', 'to', 'tarnish'] GATE_target (289, 294) id=t4 ['china'] GATE_agent (359, 379) nested-source=w,experts id=experts ['human', 'right', 'expert'] GATE_agent (259, 274) nested-source=w,experts,report nested-target=w,experts,report ['the', 'report']

  31. Continued on the next slide… "The United States was slandering China again," said Xirao-Nima, a professor of Tibetan history at the Central University for Nationalities. GATE_objective-speech-event (475, 475) nested-source=w implicit=true [] GATE_direct-subjective (523, 527) nested-source=w,nima expression-intensity=neutral attitude-link=a140 intensity=high ['say'] GATE_attitude (494, 508) intensity=high id=a140 attitude-type=sentiment-neg target-link=t5 ['be', 'slander'] GATE_target (476, 493) id=t5 ['the', 'unite', 'state'] GATE_expressive-subjectivity (498, 508) nested-source=w,nima polarity=negative intensity=high ['slander']

  32. "The United States was slandering China again," said Xirao-Nima, a professor of Tibetan history at the Central University for Nationalities. GATE_direct-subjective (494, 508) nested-source=w,nima,US polarity=negative expression-intensity=high attitude-link=a150 intensity=high ['be', 'slander'] GATE_attitude (494, 508) intensity=high id=a150 attitude-type=sentiment-neg target-link=t6 ['be', 'slander'] GATE_target (509, 514) id=t6 ['china'] GATE_agent (528, 538) nested-source=w,nima id=nima ['xirao-', 'nima'] GATE_agent (476, 493) nested-source=w,nima,US nested-target=w,nima,US id=US ['the', 'unite', 'state'] GATE_agent (509, 514) nested-target=w,nima,US,china ['china']

  33. These are all the annotations It shows that these so-called truths are not true at all," said Xirao-Nima GATE_objective-speech-event (3111, 3111) nested-source=w implicit=true [] GATE_direct-subjective (3170, 3174) attitude-type=negative intensity=high attitude-link=a350,a355expression-intensity=neutral nested-source=w,nima attitude-toward=report ['say'] GATE_attitude (3111, 3167) intensity=medium-high id=a355 attitude-type=arguing-neg target-link=t101 ['it', 'show', 'that', 'these', 'so-call', 'truth', 'be', 'not', 'true', 'at', 'all'] GATE_attitude (3111, 3167) intensity=high id=a350 attitude-type=sentiment-neg target-link=t101 ['it', 'show', 'that', 'these', 'so-call', 'truth', 'be', 'not', 'true', 'at', 'all'] GATE_target (3125, 3147) id=t101 ['these', 'so-call', 'truth'] GATE_expressive-subjectivity (3131, 3147) nested-source=w,nima polarity=negative intensity=medium ['so-call', 'truth'] GATE_expressive-subjectivity (3152, 3167) nested-source=w,nima polarity=negative intensity=high ['not', 'true', 'at', 'all'] GATE_agent (3175, 3185) nested-source=w,nima ['xirao-', 'nima']

  34. Layering with Other Annotation Schemes • E.g. Time, Lexical Semantics, Discourse… • Richer interpretations via combination • Potential disambiguation both ways • Example with the Penn Discourse Treebank (PDTB) Version 2 recently released through Language Data ConsortiumJoshi, Webber, Prasad, Miltsakaki, … http://www.seas.upenn.edu/~pdtb/

  35. Swapna will cover the following material later in the course in more detail. This is to give us an idea now.

  36. The type “Cause” is used when the connective indicates that the situations described in Arg1 and Arg2 are causally influenced and the two are not in a conditional relation …

  37. Polarity preserved across Result relation Other firms "are dealing with the masses. I don't believe they have the culture" to adequately service high-net-worth individuals, he adds.

  38. Polarity preserved across Result relation: PDTB [Other firms "are dealing with the masses ARG1]. I don't believe IMPLICIT_SO[they have the culture" to adequately service high-net-worth individuals ARG2], he adds. ARG2 is a result of ARG1

  39. Polarity preserved across Result relation: PDTB [Other firms "are dealing with the masses ARG1]. I don't believe IMPLICIT_SO[they have the culture" to adequately service high-net-worth individuals ARG2], he adds. X said Y: “X said”  X’s belief space “I don’t believe” explicit in second sentence “Swartz said” implicit in first sentence ARG spans: Dis. Rel within Swartz’s belief space

  40. Polarity preserved across Result relation: subjectivity Other firms “[are dealing with the masses SENTIMENT-NEG]. I [don't believe they have the culture" to adequately service high-net-worth individuals SENTIMENT-NEG], he adds. Attitude span includes “don’t believe”; schemes require different notions of spans

  41. Polarity preserved across Result relation: subjectivity Other firms “[are dealing with the masses SENTIMENT-NEG]. I [don't believe they have the culture" to adequately service high-net-worth individuals SENTIMENT-NEG], he adds. Two negative properties, where the second is a result of the first

  42. Polarity preserved across Result relation: subjectivity Other firms “[are dealing with the masses SENTIMENT-NEG]. I [don't believe they have the culture" to adequately service high-net-worth individuals SENTIMENT-NEG], he adds. Dis Rel between ARGS inside his belief space

  43. Polarity preserved across Result relation: subjectivity Other firms “[are dealing with the masses SENTIMENT-NEG]. I [don't believe they have the culture" to adequately service high-net-worth individuals SENTIMENT-NEG], he adds. Semantics of result: specific subtype, where a negative state of affairs is the result of another one

  44. The class tag “COMPARISON” applies when the connective indicates that a discourse relation is established between Arg1 and Arg2 in order to highlight prominent differences between the two situations.

  45. In that suit, the SEC accused Mr. Antar of engaging in a "massive financial fraud" to overstate the earnings of Crazy Eddie, Edison, N.J., over a three-year period. Through his lawyers, Mr. Antar has denied allegations in the SEC suit and in civil suits previously filed by shareholders against Mr. Antar and others.

  46. PDTB [In that suit, the SEC accused Mr. Antar of engaging in a "massive financial fraud" to overstate the earnings of Crazy Eddie, Edison, N.J., over a three-year period. ARG1] IMPLICIT_CONTRAST[ Through his lawyers, Mr. Antar has denied allegations in the SEC suit and in civil suits previously filed by shareholders against Mr. Antar and others. ARG2] Contrast between the SEC accusing Mr. Antar of something, and his denying the accusation

  47. Subjectivity In that suit, the SEC [[accused SENTIMENT-NEG] Mr. Antar of engaging in a "massive financial fraud" to overstate the earnings of Crazy Eddie, Edison, N.J. ARGUING-POS], over a three-year period. Through his lawyers, Mr. Antar [has denied AGREE-NEG] allegations in the SEC suit and in civil suits previously filed by shareholders against Mr. Antar and others. Two attitudes combined into one large disagreement between two parties

  48. Subjectivity In that suit, the SEC [[accused SENTIMENT-NEG] Mr. Antar of engaging in a "massive financial fraud" to overstate the earnings of Crazy Eddie, Edison, N.J. ARGUING-POS], over a three-year period. Through his lawyers, Mr. Antar [has denied AGREE-NEG] allegations in the SEC suit and in civil suits previously filed by shareholders against Mr. Antar and others. Subjectivity: arguing-pos and agree-neg with different sources; Hypothesis: common with contrast. Help recognize the implicit contrast.

  49. Subjectivity In that suit, the SEC [[accused SENTIMENT-NEG] Mr. Antar of engaging in a "massive financial fraud" to overstate the earnings of Crazy Eddie, Edison, N.J. ARGUING-POS], over a three-year period. Through his lawyers, Mr. Antar [has denied AGREE-NEG] allegations in the SEC suit and in civil suits previously filed by shareholders against Mr. Antar and others. Semantics of comparison: specific case of highlighting prominent differences in attitudes of different people

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