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Semantic Role Labeling
This document provides an overview of semantic role labeling in natural language processing. It discusses key concepts including predicate identification, argument identification, and argument labeling. It covers semantic roles, PropBank which annotates arguments with semantic roles, and VerbNet and FrameNet which provide semantic frames and frame elements to further specify predicate-argument relations.
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Semantic Role Labeling
- 1. Semantic Role Labeling NaturalLanguage Processin g Emory University Jinho D. Choi
- 2. Predicate Identi fi cation 2 What isa predicate? A linguistic unit that governs arguments. Cannot complete its meaning without its arguments. He bought a car from a dealer for her yesterday . He was going to buy a car . She threw the car away . He made a bid for the car . She ignored his bid to accept the car . The bid was acceptable to me. auxiliary verb verb-particle light-verb noun-predicate adjective-predicate verb-predicate
- 3. Predicate Sense Disambiguation 3 Apredicate can have multiple senses (meanings). Take He took the book with him . He couldn’t take the pressure . He took 5 days to complete the homework. http://verbs.colorado.edu/propbank/framesets-english/take-v.html http://wordnetweb.princeton.edu/perl/webwn?s=take
- 4. Argument Identi fi cation 4 What isan argument? A participant of the predicate. Complete the meaning of the predicate. She threw the car away. He made a bid for the car. She ignored his bid to accept the car. The bid was acceptable to me. He bought a car from a dealer for her yesterday. Exercise
- 5. Argument Labeling 5 She threwthe car away. He made a bid for the car. She ignored his bid to accept the car. The bid was acceptable to me. agent theme He bought a car from a dealer for her yesterday. agent theme source beneficiary temporal agent patient theme agent agent theme theme agent agent theme
- 6. Semantic Roles 6 Underlying relationsbetween predicates and their arguments. actor destination patient theme agent experiencer predicate theme asset extent product patient attribute instrument recipient time bene fi ciary location source topic cause material stimulus proposition http://verbs.colorado.edu/~mpalmer/projects/verbnet.html
- 7. Semantic Role Labeling 7 PredicateIdenti fi cation Predicate Sense Disambiguation Argument Identi fi cation Argument Labeling
- 8. PropBank 8 A corpus inwhich arguments are annotated with the semantic roles they play with respect to their predicates. Each predicate encompasses one or more senses de fi ning their own predicate argument structures. open open.01: open open.02: begin open.03: cause to be not closed ARG0: opener ARG1: thing opened ARG2: instrument ARG3: benefactive ARG0: causer of opening ARG1: thing opened ARG0: opener ARG1: thing opened ARG2: instrument ARG3: benefactive Predicate Senses Argument Structures
- 9. PropBank 9 open open.01: open open.02:begin open.03: cause to be not closed ARG0: opener ARG1: thing opened ARG2: instrument ARG3: benefactive ARG0: causer of opening ARG1: thing opened ARG0: opener ARG1: thing opened ARG2: instrument ARG3: benefactive ARG0 ARG1 ARG2 TMP
- 10. PropBank 10 open open.01: open open.02:begin open.03: cause to be not closed ARG0: opener ARG1: thing opened ARG2: instrument ARG3: benefactive ARG0: causer of opening ARG1: thing opened ARG0: opener ARG1: thing opened ARG2: instrument ARG3: benefactive ARG0 ARG1 ARG2 TMP Numbered Arguments Modi fi ers
- 11. Numbered Arguments 11 Arguments frequentlyco-occuring with their predicates. ARG0: agent . ARG1: patient, theme . ARG2: instrument, benefactive, attribute . ARG3: starting point . ARG4: ending point . ARGA: external causer. Are numbered arguments required? How do you determine numbered arguments? Semantics are overloaded!
- 12. Modi fi ers 12 Arguments whose rolesare independent from their predicates. ADJ Adjectival LOC Location ADV Adverbial MNR Manner CAU Cause MOD Modal COM Comitative NEG Negation DIR Direction PRD Secondary predication DIS Discourse PRP Purpose GOL Goal REC Recipricol EXT Extent TMP Temporal
- 13. Argument Candidates 13 No needto traverse the entire tree for fi nding the arguments! Sibling of the predicate. Dependents of the predicate.
- 14. Argument Candidates 14 Siblings ofthe ancestors. Dependents of the ancestors.
- 15. Argument Candidates 15 Linguistically motivatedrules Dependents of the predicate . Dependents of the ancestors. What if the tree is ill-parsed? 92 94 96 98 100 First-order Gold System
- 16. Argument Candidates 16 Higher-order Dependents ofthe predicate . Dependents of the ancestors. Descendents ← 92 94 96 98 100 First-order Higher-order Gold System
- 17. Applications 17 Question Answering He boughta car from a dealer for her yesterday . Who bought what from whom for whom when? ARG0 He Who ARG1 a car what ARG2 from a dealer from whom ARG4 for her for whom TMP yesterday when Predicate buy.01 buy.01
- 18. Semantic Frames 18 Semantic rolelabeling is sometimes not enough! He bought a car from a dealer . Who sold a car to him? ARG0 He Who ARG1 a car the car ARG2 from a dealer to him Predicate buy.01 sell.01 Use theVerbNet semantic frames. http://verbs.colorado.edu/verb-index/
- 19. VerbNet 19 VerbNet Semantic Frames has_possession(start(E),Source, Theme) has_possession(end(E), Agent, Theme) transfer (during(E), Theme) buy → get-13.5.1 sell → give-13.1 has_possession(start(E), Agent, Theme) has_possession(end(E), Recipient, Theme) transfer (during(E), Theme) http://verbs.colorado.edu/verb-index/vn/get-13.5.1.php http://verbs.colorado.edu/verb-index/vn/give-13.1.php
- 20. VerbNet 20 ARG0 He Who ARG1a car the car ARG2 from a dealer to him Predicate buy.01 sell.01 has_possession(start(E), Source, Theme) has_possession(end(E), Agent, Theme) transfer (during(E), Theme) buy → get-13.5.1 sell → give-13.1 has_possession(start(E), Agent, Theme) has_possession(end(E), Recipient, Theme) transfer (during(E), Theme) has_possession(start(buy), a dealer, a car) has_possession(end(buy), He, a car) transfer (during(buy), a car) has_possession(start(sell), Who, a car) has_possession(end(sell), him, a car) transfer (during(sell), a car)
- 21. FrameNet 21 Frame Semantics The meaningof a word cannot be understood without a frame of semantic knowledge relating to the speci fi c concept it refers to. Semantic Frame A description of event, relation, or entity and the participants in it. apply_heat, cooking_creation, revenge Lexical Units Words that belong to the same semantic frame. revenge → avenge.v, avenger.n, get_even.v, payback.n, retaliate.v, … vs. verb classes? vs. PA structures? https://framenet.icsi.berkeley.edu
- 22. FrameNet Elements 22 Core FrameElement revenge → avenger, injured party, injury, offender, punishment Instantiates a conceptually necessary component of a frame. Non-core Frame Element Can be instantiated in any semantically appropriate frame. revenge → degree, depictive, duration, instrument, manner, … vs. numbered args? vs. modi fi ers? Semantic Type The type of a frame element to be broadly constant across uses. e.g., sentient, physical entity, state of affairs, temperature, etc.
- 23. FrameNet Relations 23 Coreness Set Revenge→ {injured party, injury}, {avenger, punishment} A set of frame elements in that the presence of a member of the set is suf fi cient to satisfy a semantic valence of its predicate. Requires The occurrence of a core FE requires another core FE to occur. The robber tied Harry to the chair. Excludes The occurrence of a core FE excludes other core FEs to occur. The robber tied Harry’s ankles together. item goal items
- 24. Semantic Frames 24 Apply Heat cookcontainer food heatin g instrument tempora l setting container sentient physical entity temperature bene fi ciary co-participant degree duration manner means place medium purpose time Semantic Frame Core FE Non-core FE Semantic Type Core Set bake.v, barbecue.v, blanch.v, boil.v, braise.v, broil.v, etc. Lexical Unit
- 25. Frame Inheritance andRelations 25 Apply Heat Activity Process Internally affect Internally act Transitive action Event Objective in fl uence Cooking creation Absorb heat is used by is causative of Frame Inheritance Frame Relations
- 26. Sub-Frames and Precedence 26 Crime scenario Committing crime Criminal investigation Criminal process Arraignment ArrestSentencing Trial Bail decision Entering of plea Noti fi cation of charges Cour t examination Jury deliberation Verdict
- 27. Paraphrase 27 John e-mailed Maryhis info. John communicated his info to Mary by e-mail. Contractin g e-mail John Mary his info Communicatio n communicate John his info Mary e-mail Communicator Addressee Uses Communicator Addressee Topic Mean Topic
- 28. Frame Elements 28 Frame Semantics Themeaning of a word cannot be understood without a frame of semantic knowledge relating to the speci fi c concept it refers to. Semantic Frame A description of event, relation, or entity and the participants in it. apply_heat, cooking_creation, revenge Semantic Frame vs. Predicate Argument Structures?