Desired situation Syntactic vs. Semantic Knowledge for Supervised Learning of Textual Manually Entailment Entailment Entailment Recognition data annotated analyzer entailments Abstract Machine computational Learning Yoad Winter model Utrecht University In the absence of general model: Semantic Representations for Textual Inference - Not much annotated data CSLI, Stanford, March 9-10, 2012 - Little understanding of modularity in entailment Joint work in progress with: Sophia Katrenko, Assaf Toledo a.o. (Utrecht), systems Ido Dagan a.o. (Bar Ilan) 1 3 Simplified Models? Entailment Grammaticality • Constituency Partial order on well-formed sentences • Dependency Translation and Paraphrasing = ~ bi-entailment agreement, extraction, subcategorization etc. Entailment General question: No simplified semantic model. Can entailment be automatically acquired In full generality, perhaps close to Turing using methodologies familiar from acquisition of stochastic parsers? test. Î Rely on simplified models, simplified data, or both. 2 4
Analyzing entailments Two general approaches Question: Restricted How can current entailment data be best analyzed Selecting to improve system evaluation and modularity? Model and (and/or) Special Annotation Entailments Suggested approach: For phenomena that are: For sparser and non- Analyze those phenomena that are: - Useful for many RTE surface phenomena that - Common in RTE data systems reveal limitations of - Commonly used (w or w/o analysis) by current engines - Surface level current engines - Easiest to analyze on the surface Joint work with: Utrecht: Sophia Katrenko, Assaf Toledo, Stavroula Aim: improving evaluation, modularity, Alexandropulou, Heidi Klockmann and ultimately learnability Bar Ilan: Ido Dagan, Ahser Stern, Amnon Lotan 5 7 Two general approaches Entailment analysis Entailment is analyzed as made up of Restricted Selecting small pieces of local semantic relations . Model and (and/or) Special Annotation Entailments Analyzing entailments consists of aligning and classifying elements of Focus of this talk Work in progress with Danilo Giampiccollo, these relations in text and hypothesis. Emanuele Pianta a.o. (CELCT, Trento) Distinguish between: Lexical relations Structural relations 6 8
Lexical relations - example Semantics of adjuncts: Restriction vs. Apposition Jakarta’s main industries are the production of chemicals and plastics Jakarta’s main industries are the production of chemicals and plastics Jakarta’s products include chemicals and plastics Jakarta’s products include chemicals and plastics ADJ X: identity Lexical relations: Restriction: ADJ X is subsumed by X X’s main Y’s are Z Î X’s Y’s include Z X’s industries are the production of Y Î X’s products are Y Apposition: ADJ is predicated over X Common in RTE, but data are sparse. Î Concentrate on structural relations. 9 11 Structural relations – example Restriction – Semantics Senator Hill and Foreign Affairs Minister Alexander Downer will host the 20th annual AUSMIN (Australia-United States ministerial consultations) conference at the Adelaide Town Hall Î Alexander Downer will host a conference Î Î Î - Conjunction: Senator Hill and Foreign Affairs Minister Alexander Downer Î Foreign Affairs Minister Alexander Downer - Apposition/Restrictive adjunct: Foreign Affairs Minister Alexander Downer Î Alexander Downer - Definite/indefinite entailment: the [ 20th annual AUSMIN (Australia-United States ministerial consultations) conference at the Adelaide Town Hall ] Î a [ 20th annual AUSMIN (Australia-United States ministerial consultations) conference at the Adelaide Town Hall ] - Restrictive adjuncts: [ [ 20th annual AUSMIN (Australia-United States ministerial consultations) ] conference [ at the Adelaide Town Hall ] ] Î Î [ 20th annual AUSMIN (Australia-United States ministerial Î Î consultations) ] conference Î conference Î Î Î 10
Restriction – Examples Apposition – Semantics Restriction supports adjunct omission in MON environments: Appositive adjunct: John is a tall man Î John is a man An adjunct ADJ is appositive iff for every John ran quickly Î John ran grammatical constituent ADJ X: John is a man who runs Î John is a man ADJ is predicated of X. John is tall and thin Î John is tall 13 15 Intersection – Examples Apposition – Examples (1) Intersection – modifee omission in MON environments plus adjunct change: Adjunct omission (in all environments): Prof. Smith ran Î Smith ran John is a tall man Î John is tall Nobody likes Prof. Smith Î Nobody likes Smith John ran quickly Î There was a quick running (by John) John, who is a/the teacher, ran Î John ran John is a man who runs Î John runs John, a/the teacher, ran Î John ran John is tall and thin Î John is thin This kind of omission appears in RTE data, but not often: Iran will soon release eight British servicemen detained along with three vessels Î British servicemen (were) detained Î Î Î 14 16
Set F and its annotation Apposition – Examples (2) - Appositions - Titles Predication: - Conjunctions Prof. Smith ran Î Smith is a Prof. early a restrictive modifier of - Relatives Nobody likes Prof. Smith Î Smith is a Prof. Thursday , but this does not contribute to entailment - Other adjuncts John, who is a/the teacher, ran Î John is a/the teacher When to annotate? Only when phenomenon John, a/the teacher, ran Î John is a/the teacher contributes to entailment. Only a week after it had no comment on upping the storage capacity of its Hotmail e-mail service, Microsoft early Thursday announced it was boosting the allowance to 250MB to follow similar moves by rivals such as Google, Yahoo, and Lycos. Î Microsoft's Hotmail has raised its storage capacity to 250MB. 17 19 Structural annotation guidelines The two surface-level phenomena Omission of adjunct 1. Read the Hypothesis ADJ X Î Î X’, Î Î Restrictive adjuncts 2. Read the Text and verify the entailment where X Î X’ Appositives 3. Describe informally (in text) why the Conjunctions (X’ may or may not equal X) entailment holds (inc. Relatives) 4. Annotate each phenomenon occurrence f from set F such that f is used in inference Predication using modifier ADJ X Î Î Î Î X’ is ADJ, Intersective adjuncts where X Í Í Í ÍÎ X’ Appositives (inc. Relatives) (X’ may or may not equal X) 18 20
Restrictive adjunct omission – modifiers Appositive adjunct omission ADJ X Î Î Y, where X Î Y (X may or may not equal Y) Î Î ADJ X Î Î Î Î Y, where X Î Y (X may or may not equal Y) These early men learned to make fire. They traveled over land bridges Brought under Ottoman rule in the 16th century, Jordan has been from Africa, and began to populate the world, about 1 million years ago. led only since the 1920s by Hashemite rulers, a family whose Î Î Humans existed 10,000 years ago. Î Î roots are in present-day Saudi Arabia . Î The Hashemite dynasty rules Jordan. Tropical Storm Debby is blamed for several deaths across the Caribbean. Î A tropical storm has caused loss of life. German automaker, Volkswagen AG, launched a special A joint venture led by Australia's Global Petroleum Ltd. said, yesterday, it collector's edition of its original Beetle, on Thursday, to mark the had won the right to explore for oil and gas in the inhospitable waters end of the line for the most popular car in history. south and east of the Falkland Islands. Î Petroleum will be explored in the South Atlantic. Î Volkswagen AG produces the 'Beetle'. Guggenheim Museum, officially Solomon R. Guggenheim Museum, was founded in 1939 as the Museum of Non-Objective Art. Î The Solomon R. Guggenheim Museum was opened in 1939. 21 23 Appositive adjunct – predication Restrictive adjunct omission – conjuncts ADJ X Î Î X’ is ADJ, where X Í Î Î ÍÎ X’ Í Í ADJ X Î Î Y, where X Î Y (X may or may not equal Y) Î Î (X’ may or may not equal X) Some plants grow really well in a hydroponic environment, but Muslim fundamentalists such as the Islamic Resistance Movement, also known as others do not . Hamas , and the smaller Islamic Jihad are determined to torpedo the peace process. Î Plants are grown in water or in substances other than soil. Î The Islamic Resistance Movement is also known as Hamas . The two young leaders of the coup, Pibul Songgram and Pridi Phanomyang , both The ivory ban has been successful. Demand for ivory has educated in Europe and influenced by Western ideas, came to dominate Thai politics in dropped and elephant populations expanded dramatically in the ensuing years. areas where they were virtually extinct. Î Pibul was a young leader. ( also Conjunction and Adjunct Omission ) Î Î Î Î The ban on ivory trade has been effective in protecting the In a move reminiscent for some of another actor, Ronald Reagan, who was twice elephant from extinction. elected governor of California , Schwarzenegger said he would be putting his movie career on hold so he can devote his time to running for governor. Î Ronald Regan was elected governor of California. ( also Adjunct Omission ) 22 24
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