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Probabilistic Frame-Semantic Parsing Noah A. Smith Dipanjan Das Nathan Schneider Desai Chen School of Computer Science Carnegie Mellon University NAACL-HLT June 4, 2010 In a Nutshell Most models for semantics are very local (cascades of


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Probabilistic Frame-Semantic Parsing

Dipanjan Das Nathan Schneider Desai Chen

Noah A. Smith

NAACL-HLT June 4, 2010

School of Computer Science Carnegie Mellon University

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Das, Schneider, Chen and Smith, NAACL-HLT 2010

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In a Nutshell

  • Most models for semantics are very local

(cascades of classifiers)

  • This work: towards more global modeling for rich

semantic processing (feature sharing among all semantic classes) (just two probabilistic models)

  • Our model outperforms the state of the art
  • Our framework lends itself to extensions and

improvements

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  • Introduction
  • Background and Datasets
  • Models and Results
  • Conclusion

Outline

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Das, Schneider, Chen and Smith, NAACL-HLT 2010

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  • Introduction
  • Background and Datasets
  • Models and Results
  • Conclusion

Outline

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Overview

  • Annotate English sentences with semantic

representations

  • Combination of:
  • semantic frame (word sense) disambiguation
  • semantic role labeling
  • Frame and role repository: FrameNet (Fillmore et al., 2003)
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Das, Schneider, Chen and Smith, NAACL-HLT 2010

  • Theory developed by Fillmore (1982)
  • a word evokes a frame of semantic knowledge
  • a frame encodes a gestalt event or scenario
  • it has conceptual dependents filling roles

elaborating the frame instance

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Frame Semantics

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Das, Schneider, Chen and Smith, NAACL-HLT 2010

  • Theory developed by Fillmore (1982)
  • a word evokes a frame of semantic knowledge
  • a frame encodes a gestalt event or scenario
  • it has conceptual dependents filling roles

elaborating the frame instance

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the 1995 book by John Grisham

Frame Semantics

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Das, Schneider, Chen and Smith, NAACL-HLT 2010

  • Theory developed by Fillmore (1982)
  • a word evokes a frame of semantic knowledge
  • a frame encodes a gestalt event or scenario
  • it has conceptual dependents filling roles

elaborating the frame instance

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the 1995 book by John Grisham

TEXT

Frame Semantics

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Das, Schneider, Chen and Smith, NAACL-HLT 2010

  • Theory developed by Fillmore (1982)
  • a word evokes a frame of semantic knowledge
  • a frame encodes a gestalt event or scenario
  • it has conceptual dependents filling roles

elaborating the frame instance

9

the 1995 book by John Grisham

  • a frame encodes a gestalt event or scenario

Frame Semantics

TEXT

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Das, Schneider, Chen and Smith, NAACL-HLT 2010

  • Theory developed by Fillmore (1982)
  • a word evokes a frame of semantic knowledge
  • a frame encodes a gestalt event or scenario
  • it has conceptual dependents filling roles

elaborating the frame instance

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the 1995 book by John Grisham

  • a frame encodes a gestalt event or scenario

Author Time_of_creation

  • it has conceptual dependents filling roles

elaborating the frame instance

Frame Semantics

TEXT

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FrameNet

(Fillmore et al., 2003)

MAKE_NOISE Noisy_event Sound Sound_source Place Time

cough.v, gobble.v, hiss.v, ring.v, yodel.v, ...

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Das, Schneider, Chen and Smith, NAACL-HLT 2010

MAKE_NOISE Noisy_event Sound Sound_source Place Time

cough.v, gobble.v, hiss.v, ring.v, yodel.v, ...

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lexical units frame roles

(Fillmore et al., 2003)

FrameNet

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relationships between frames and between roles

EVENT Place Time Event TRANSITIVE_ACTION Agent Patient Event Cause Place Time OBJECTIVE_INFLUENCE Dependent_entity Influencing_situation Place Time Influencing_entity CAUSE_TO_MAKE_NOISE Agent Sound_maker Cause Place Time MAKE_NOISE Noisy_event Sound Sound_source Place Time

cough.v, gobble.v, hiss.v, ring.v, yodel.v, ... blare.v, honk.v, play.v, ring.v, toot.v, ... — affect.v, effect.n, impact.n, impact.v, ... event.n, happen.v,

  • ccur.v, take place.v, ...

Inheritance relation Causative_of relation Excludes relation

Purpose

(Fillmore et al., 2003)

FrameNet

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  • Statistics:
  • 795 semantic frames
  • 7124 roles
  • 8379 lexical units (predicates)
  • 139,000 exemplar sentences containing one frame

annotation per sentence

FrameNet

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Marco Polo wrote an account of Asian society during the 13th century .

TEXT Author Topic

A Frame-Semantic Parse

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Marco Polo wrote an account of Asian society during the 13th century .

TEXT Author Topic

here, the ambiguous word evokes the TEXT frame

A Frame-Semantic Parse

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Marco Polo wrote an account of Asian society during the 13th century .

TEXT Author Topic

participants in the event or scenario

A Frame-Semantic Parse

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Marco Polo wrote an account of Asian society during the 13th century .

TEXT Author Topic

A Frame-Semantic Parse

frame-specific

participants in the event or scenario

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Why Frame-Semantic Parsing?

  • Combines lexical and predicate-argument semantics
  • Exploits meaningful primitives developed by experts
  • the FrameNet lexicon
  • Richer representation than PropBank style SRL
  • No inconsistent symbolic tags (ARG2-ARG5)

(Yi et al. 2007, Matsubayashi et al. 2009)

  • Patterns generalizing across frames and roles can be learned

(Matsubayashi et al. 2009)

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  • Introduction
  • Background and Datasets
  • Models and Results
  • Conclusion

Outline

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Early Work

  • Gildea and Jurafsky (2002)
  • Much smaller version of FrameNet
  • exemplar sentences
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SemEval 2007

  • Baker et al. (2007) organized the SemEval task on

frame structure extraction

  • first set of full text annotations available
  • released a corpus of ~2000 sentences with full

frame-semantic parses

  • Johansson and Nugues (2007) submitted the best

performing system

  • our baseline for comparison (J&N’07)
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SemEval 2007

  • SemEval 2007 dataset:
  • training set: 1941 sentences
  • test set: 120 sentences
  • Three domains
  • American National Corpus (travel)
  • Nuclear Threat Initiative (bureaucratic)
  • PropBank (news)
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SemEval 2007

  • Evaluation is done using the official SemEval script
  • Measures precision, recall and F1 score for

frames and arguments

  • Features a partial matching criterion for frame

identification

  • assigns score between 0 and 1 to closely

related frames in the FrameNet hierarchy

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  • Introduction
  • Background and Datasets
  • Models and Results
  • Conclusion

Outline

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Challenges

  • Several times more labels than traditional

shallow semantic parsing

  • Annotated data does not have gold

syntactic annotation

  • Very little labeled data
  • Identifying semantic frames for unknown

lexical units

  • Very sparse features
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Desired Structure

Everyone in Dublin seems intent on changing places with everyone else .

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Desired Structure

Everyone in Dublin seems intent on changing places with everyone else .

LOCATIVE_RELATION Figure Ground LOCALE Locale EXCHANGE Exchanger_1 Exchanger_2 Themes

PURPOSE

Agent Goal Phenomenon

APPEARANCE

Inference

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Three Subtasks:

  • Target identification
  • Identifying frame-evoking predicates

(nontrivial!)

  • Frame identification
  • Labeling each target with a frame type

(795 possibilities; ~WSD)

  • Argument identification
  • Finding each frame's arguments

(~SRL; roleset is frame-specific)

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Three Subtasks:

  • Target identification
  • Identifying frame-evoking predicates

(nontrivial!)

  • Frame identification
  • Labeling each target with a frame type

(795 possibilities; ~WSD)

  • Argument identification
  • Finding each frame's arguments

(~SRL; roleset is frame-specific)

sentence

predicates frames frames and arguments

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Three Subtasks:

  • Target identification
  • Identifying frame-evoking predicates

(nontrivial!)

  • Frame identification
  • Labeling each target with a frame type

(795 possibilities; ~WSD)

  • Argument identification
  • Finding each frame's arguments

(~SRL; roleset is frame-specific)

sentence

predicates frames frames and arguments

rule-based

probabilistic probabilistic

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  • Introduction
  • Background and Datasets
  • Models and Results
  • Target Identification
  • Frame Identification
  • Argument Identification
  • Final Results
  • Conclusion

Outline

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Target Identification

Everyone in Dublin seems intent on changing places with everyone else .

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  • Rule-based identification
  • list of all morphological variants of predicates in the lexicon
  • all prepositions filtered
  • support verbs were not identified
  • J&N’07 filtered these

Target Identification

Everyone in Dublin seems intent on changing places with everyone else .

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  • Introduction
  • Background and Datasets
  • Models and Results
  • Target Identification
  • Frame Identification
  • Argument Identification
  • Final Results
  • Conclusion

Outline

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Frame Identification

Everyone in Dublin seems intent on changing places with everyone else .

LOCATIVE_RELATION LOCALE EXCHANGE

PURPOSE APPEARANCE

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Frame Identification

Everyone in Dublin seems intent on changing places with everyone else .

LOCATIVE_RELATION LOCALE EXCHANGE

PURPOSE APPEARANCE

J&N’07 used several classifiers for this subtask

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Unseen LUs

from WordNet-extended set

sixth ∈ ORDINAL_NUMBERS? Y N

Seen LUs

sixth ∈ RELATIVE_TIME? sixth ∈ INGESTION?

… 1 classifier … 795 classifiers

Frame Identification

(Johansson and Nugues, 2007)

place

LOCALE PLACING

book in

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Unseen LUs

from WordNet-extended set

intent ∈ PURPOSE? Y N

Seen LUs

intent ∈ AIMING? intent ∈ INGESTION?

… 1 classifier … 795 classifiers

Frame Identification

(Johansson and Nugues, 2007)

place

LOCALE PLACING

book in

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Frame Identification

Our approach: One single model for frame identification

Everyone in Dublin seems intent on changing places with everyone else .

LOCATIVE_RELATION LOCALE EXCHANGE

PURPOSE APPEARANCE

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NN IN NNP VBZ NN IN VBG NNS IN NN RB .

Frame Identification

Assume POS tags and dependency trees to be given

Everyone in Dublin seems intent on changing places with everyone else .

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Frame Identification

Assume that target is connected to the frame through a prototype unit

t ℓ f t ℓ

f

NN IN NNP VBZ NN IN VBG NNS IN NN RB .

Everyone in Dublin seems intent on changing places with everyone else .

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NN

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Frame Identification

PURPOSE

Assume that target is connected to the frame through a prototype unit

t ℓ f

?

NN IN NNP VBZ IN VBG NNS IN NN RB .

Everyone in Dublin seems intent on changing places with everyone else .

t ℓ

f

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Frame Identification

PURPOSE Goal Means Agent

aim.n, goal.n, object.n,

  • bjective.n, purpose.n,

target.n

Attribute Value

  • Consider the PURPOSE frame
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Frame Identification

PURPOSE Goal Means Agent

aim.n, goal.n, object.n,

  • bjective.n, purpose.n,

target.n

Attribute Value

{ }

ℓ∈

  • Consider the PURPOSE frame
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Frame Identification

PURPOSE Goal Means Agent

aim.n, goal.n, object.n,

  • bjective.n, purpose.n,

target.n

Attribute Value

{ }

ℓ∈

note that the target intent is unseen

  • Consider the PURPOSE frame
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  • Consider the PURPOSE frame

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Frame Identification

PURPOSE Goal Means Agent

aim.n, goal.n, object.n,

  • bjective.n, purpose.n,

target.n

Attribute Value

{ }

ℓ∈

note that the target intent is unseen

but lexical semantic relationships between some and the target exist

purpose ≈ intent

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Thus, we define a probabilistic model: Frame Identification

pθ(f, ℓ | t, x) ∝ exp θ⊤g(f, ℓ, t, x)

NN IN NNP VBZ NN IN VBG NNS IN NN RB .

Everyone in Dublin seems intent on changing places with everyone else .

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Thus, we define a probabilistic model: Frame Identification

pθ(f, ℓ | t, x) ∝ exp θ⊤g(f, ℓ, t, x)

WordNet relationships!

some features looking at the lexical and semantic relationships between and

ℓ f

NN IN NNP VBZ NN IN VBG NNS IN NN RB .

Everyone in Dublin seems intent on changing places with everyone else .

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  • ther features looking at the

whole sentence structure

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Thus, we define a probabilistic model: Frame Identification

pθ(f, ℓ | t, x) ∝ exp θ⊤g(f, ℓ, t, x) x

NN IN NNP VBZ NN IN VBG NNS IN NN RB .

Everyone in Dublin seems intent on changing places with everyone else .

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Thus, we define a probabilistic model: Frame Identification

pθ(f, ℓ | t, x) ∝ exp θ⊤g(f, ℓ, t, x)

Note that is unknown

NN IN NNP VBZ NN IN VBG NNS IN NN RB .

Everyone in Dublin seems intent on changing places with everyone else .

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Thus, we define a probabilistic model: Frame Identification

pθ(f, ℓ | t, x) ∝ exp θ⊤g(f, ℓ, t, x)

Marginalization of latent variable:

pθ(f | t, x) ∝

exp θ⊤g(f, ℓ, t, x)

NN IN NNP VBZ NN IN VBG NNS IN NN RB .

Everyone in Dublin seems intent on changing places with everyone else .

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Frame Identification Inference:

NN IN NNP VBZ NN IN VBG NNS IN NN RB .

Everyone in Dublin seems intent on changing places with everyone else .

ˆ f ← argmaxf

exp θ⊤g(f, ℓ, t, x)

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Frame Identification Inference: Training: maximum conditional likelihood

NN IN NNP VBZ NN IN VBG NNS IN NN RB .

Everyone in Dublin seems intent on changing places with everyone else .

ˆ f ← argmaxf

exp θ⊤g(f, ℓ, t, x)

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Results

50 57 64 71 78 J&N’07 This Work This Work

74.2 68.3 64.0 74.2 61.0 56.4 74.2 77.5 73.9

Precision Recall F1

(Oracle Targets) (Model Targets)

Frame Identification

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Results

50 57 64 71 78 J&N’07 This Work This Work

74.2 68.3 64.0 74.2 61.0 56.4 74.2 77.5 73.9

Precision Recall F1

(Oracle Targets) (Model Targets)

Frame Identification

significant improvement

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Frame Identification

  • For gold standard targets, 210 out of 1058 lemmas

were unseen

  • 190 of these get some positive score for partial

frame matching

  • 4 of these exactly match
  • 44 get 0.5 or more, indicating close match
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  • Introduction
  • Background and Datasets
  • Models and Results
  • Target Identification
  • Frame Identification
  • Argument Identification
  • Final Results
  • Conclusion

Outline

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Argument Identification

Everyone in Dublin seems intent on changing places with everyone else .

EXCHANGE Exchanger_1 Exchanger_2 Themes

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Candidate spans

Two steps:

Argument Identification: The traditional approach

Everyone in Dublin

......

in Dublin

  • n changing places

changing places with everyone else places everyone

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Everyone in Dublin

......

Candidate spans

Two steps:

Argument Identification: The traditional approach

in Dublin

  • n changing places

changing places with everyone else places everyone

binary filtering potential arguments

✗ ✗ ✗ ✗ ✔ ✔

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Everyone in Dublin

......

Candidate spans

Two steps:

Argument Identification: The traditional approach

in Dublin

  • n changing places

changing places with everyone else places everyone

✔ ✔ ✗ ✗ ✗ ✗ ✔

Exchanger_1 Exchanger_2 Themes

classification of arguments into different roles

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Everyone in Dublin

......

Candidate spans

Two steps:

Argument Identification: The traditional approach

in Dublin

  • n changing places

changing places with everyone else places everyone

✔ ✔ ✗ ✗ ✗ ✗ ✔

Exchanger_1 Exchanger_2 Themes

Two steps unnecessary

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......

Candidate spans Roleset for EXCHANGE

Argument Identification: Our approach

...

Everyone in Dublin in Dublin

  • n changing places

changing places with everyone else places everyone

Exchanger_1 Exchanger_2 Exchangers Theme_1 Theme_2 Themes Manner Means

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......

Candidate spans

Exchanger_1 Exchanger_2 Exchangers Theme_1 Theme_2 Themes Manner Means

Roleset for EXCHANGE

Argument Identification: Our approach

...

Everyone in Dublin in Dublin

  • n changing places

changing places with everyone else places everyone

  • ne step!

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A probabilistic model: Argument Identification

pψ(r → s | f, t, x) ∝ exp ψ⊤h(r, s, f, t, x)

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A probabilistic model: Argument Identification

pψ(r → s | f, t, x) ∝ exp ψ⊤h(r, s, f, t, x)

features looking at the span, the frame, the role and the observed sentence structure

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Argument Identification A probabilistic model:

pψ(r → s | f, t, x) ∝ exp ψ⊤h(r, s, f, t, x)

Decoding: Best span for each role is selected For each frame, the best set of non-

  • verlapping arguments is decoded

together

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Argument Identification A probabilistic model:

pψ(r → s | f, t, x) ∝ exp ψ⊤h(r, s, f, t, x)

Training: Maximum conditional likelihood

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Results

50.000 59.572 69.145 78.717 88.290 Model Spans Oracle Spans

81.0 68.5 74.8 60.6 88.3 78.7

Precision Recall F1

Argument identification only, with gold targets and frames Argument Identification

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  • Introduction
  • Background and Datasets
  • Models and Results
  • Target Identification
  • Frame Identification
  • Argument Identification
  • Final Results
  • Conclusion

Outline

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Results

30.00 38.75 47.50 56.25 65.00 J&N’07 This work

50.2 45.6 41.9 38.4 62.8 56.0

Precision Recall F1

full frame-semantic parsing Full Frame-Semantic Parsing

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Results

30.00 38.75 47.50 56.25 65.00 J&N’07 This work

50.2 45.6 41.9 38.4 62.8 56.0

Precision Recall F1

full frame-semantic parsing

significant improvement

Full Frame-Semantic Parsing

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Conclusion

  • Best results to date on frame-semantic parsing
  • Only two probabilistic models instead of a cascade of

classifiers for the frame-semantic parsing task

  • Latent variable model for frame identification
  • Better modeling of the argument identification (SRL)

stage using only one model instead of two

  • Publicly available software: http://www.ark.cs.cmu.edu/SEMAFOR
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Thanks!

http://www.ark.cs.cmu.edu/SEMAFOR

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Thanks!

http://www.ark.cs.cmu.edu/SEMAFOR

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