1. 1 Attributions and Private States Jan Wiebe (U. Pittsburgh) Theresa Wilson (U. Pittsburgh) Claire Cardie (Cornell U.)

2. 2 Terminology Private states: opinions, emotions, evaluations, speculations, etc. States not open to objective observation or verification: “a person may be observed to assert that God exists, but not to believe that God exists. Belief is this sense ‘private’” [Quirk et al. 1985] Following literary theorists such as Banfield (1982): we use the term subjectivity for linguistic expressions of private states

3. 3 Objective speech event source: implicit: true “The U.S. fears a spill-over,” said Xirao-Nima. Direct subjective text anchor: fears source: intensity: medium expression intensity: medium Objective speech event text anchor: said source: “The report is full of absurdities,” Xirao-Nima said. Objective speech event source: implicit: true Direct subjective text anchor: said source: intensity: high expression intensity: neutral attitude: negative target: the report Expressive subjective element text anchor: full of absurdities source: intensity: high

4. 4 MPQA Opinion Corpus English language versions of articles from the world press. 187 news sources. 708 docs 15,644 sentences [385 docs expression level polarity] nrrc.mitre.org/NRRC/publications.htm Est. 415 hours to annotate 100K words Text anchor agreement: 72-82% Subjective/objective agreement:.77-.89 Kappa [Wilson & Wiebe SIGdial-03; Wilson, Wiebe, Hwa AAAI-04] [Wiebe, Wilson, Cardie LRE 1(2) 2005]

5. 5 Recent Extensions I think people are happy because Chavez has fallen. explicit private state span: are happy source: attitude: inferred attitude span: are happy because Chavez has fallen type: negative attitude intensity: medium target: target span: Chavez has fallen target span: Chavez attitude span: are happy type: positive attitude intensity: medium target: explicit private state span: think source: attitude: attitude span: think type: positive arguing intensity: medium target: target span: people are happy because Chavez has fallen

6. 6 Applications Multi-perspective QA Information extraction Tracking attitudes toward topics and events Classifying reviews Analyzing product reputations Recognizing hostile messages [Acknowledgments: Northeast Regional Research Center; ARDA AQUAINT; NSF]