1. UNED at PASCAL RTE-2 Challenge IR&NLP Group at UNED nlp.uned.es Jesús Herrera Anselmo Peñas Álvaro Rodrigo Felisa Verdejo

2. Outline  Underlying thesis  Overall architecture  Lexical Entailment  Entailment decision  Results  Conclusion & future Work

3. Underlying Thesis Compositional meaning of the statements All “components” of the hypothesis must be entailed Definition of “statement component” Our Roadmap: 1. Word & multiword level 2. NE, numeric & temporal expressions level 3. Phrase level & paraphrase (in progress)

4. Overall Architecture Dependency Parser NE Recognizer Linguistic Processing WN-based Entailment NE Entailment Lexical Entailment Decision Sentence Matching Sentence Entailment

5. WN-based Lexical Entailment  WordNet based entailment Synonymy Hyponymy( Herrera et al. 2005) Antonymy Verb Entailment Part meronymyItaly entails Europe PertainymyItalian entails Italy (Glosses)  Search of entailment paths Depth Breadth Path Length

6. WN-based Lexical Entailment 10% 1% 3%

7. Numerical Entailment 17 million citizensMore than 15 million people TextHypothesis recognize Lower bound: 17,000,000 Upper bound: 17,000,000 Unit: citizen Lower bound: 15,000,000 Upper bound: infinite Unit: person normalize Entailment is TRUE if [17,000,000.. 17,000,000]  [15,000,000.. Infinite) and citizen entails person entailment

8. Numerical Entailment

9. Entailment Decision  Support Vector Machines % of hypothesis lemmas entailed % of hypothesis words coincidence Existence of numeric expressions not entailed in the hypothesis Existence of NE not entailed in the hypothesis (after submission)

10. Results Run 1Run 2 (+word coincidence) (+NE entailment) IE49.0%52.0%51.0% QA56.5%52.0%53.5% IR64.5%57.0%63.5% SUM69.0%74.5%74.0% Overall59.75%58.87%60.5%

11. Conclusion & Future Work  WN is nice but doesn’t help too much with an indiscriminate use (Check by source task)  Different processing for each source task  NE & numerical entailment seem promising  Pay more attention to the entailment decision Future  Phrase level entailment  Paraphrase