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Statistical Models for Frame-Semantic Parsing
Dipanjan Das*
GoogleFrame Semantics in NLP: A Workshop in Honor of Chuck Fillmore
June 27, 2014
*Thanks to Desai Chen, Kuzman Ganchev, Karl Moritz Hermann, André Martins, Nathan Schneider, Noah Smith and Jason Weston
Frame-Semantic Parsing
I want to travel to Baltimore on Sunday
2
I want to travel to on Sunday
TRAVEL Encodes an event or scenario
Baltimore
Frame-Semantic Parsing
3
I want to travel to on Sunday
TRAVEL Participant or role for the
frameTravelerTime
GoalBaltimore
Frame-Semantic Parsing
4
I want to travel to on Sunday
TRAVEL Participant or role for the
frameTravelerTime
GoalBaltimore
Frame-Semantic Parsing
DESIRING
Experiencer Event
5
Outline
• Why should we build statistical models for frame semantics?
• Overview of statistical methods
• Future directions
6
Outline
• Why should we build statistical models for frame semantics?
• Overview of statistical methods
• Future directions
7
Motivation
8
Motivation
Deeper understanding beyond syntax
8
Motivation
Deeper understanding beyond syntax
Grouping of predicates and argumentsinto clusters
8
Motivation
Deeper understanding beyond syntax
Grounding of natural language to an ontology
Grouping of predicates and argumentsinto clusters
8
Motivation
Bengal ’s massive stock of food was reduced to nothing
Motivation
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
Store or financial entity?
Motivation
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
Store of what?Of what size?Whose store?
Motivation
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
Store of what?Of what size?Whose store?
Motivation
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
What was reduced?To what?
Motivation
Bengal ’s massive stock of food wasreducedto nothingN X A N ADP N V V ADP N
What was reduced?To what?
Motivation
Bengal ’s massive stock of food wasreducedto nothingN X A N ADP N V V ADP N
Bengal ’s massive stock of food was reduced to nothing
STOREPossessor
DescResource
CAUSE_CHANGE_OF_POSITION_ON_A_SCALE
Value_2Item
Motivation
Motivation
Motivation
James Cameron directed Titanic
BEHIND_THE_SCENES
Artist Production
Motivation
James Cameron directed Titanic
BEHIND_THE_SCENES
Artist Production
James Cameron is Titanic’s director
BEHIND_THE_SCENES
ProductionArtist
Motivation
James Cameron directed Titanic
BEHIND_THE_SCENES
Artist Production
James Cameron is Titanic’s director
BEHIND_THE_SCENES
ProductionArtist
Grouping across syntactic categories
Motivation
James Cameron filmed Titanic
BEHIND_THE_SCENES
Artist Production
James Cameron is Titanic’s director
BEHIND_THE_SCENES
ProductionArtist
Grouping across different lemmas
Motivation
James Cameron filmed Titanic
film.01
ARG0
James Cameron is Titanic’s director
director.01
ARG2ARG0
ARG1from
PropBank
fromNomBank
Motivation
James Cameron filmed Titanic
film.01
ARG0
James Cameron is Titanic’s director
director.01
ARG2ARG0
ARG1from
PropBank
fromNomBank
Hard to align different lemmas across resources
Motivation
James Cameron filmed Titanic
film.01
ARG0
James Cameron is Titanic’s director
director.01
ARG2ARG0
ARG1from
PropBank
fromNomBank
Very generic argument labels
Motivation
James Cameron filmed Titanic
film.01
ARG0
James Cameron is Titanic’s director
director.01
ARG2ARG0
ARG1from
PropBank
fromNomBank
Argument labels do not match up
Motivation
James Cameron filmed Titanic in 1997
BEHIND_THE_SCENES
ArtistProduction
Motivation
James Cameron filmed Titanic in 1997
BEHIND_THE_SCENES
ArtistProduction
�e.filmed.arg1(e, James Cameron)^filmed.arg2(e,Titanic)^filmed.in(e, 1997)
�e.filmed.arg1(e, /m/03 gd) ^ filmed.arg2(e, /m/0dr 4) ^ filmed.in(e, 1997)
Motivation
James Cameron filmed Titanic in 1997
BEHIND_THE_SCENES
ArtistProduction
�e.filmed.arg1(e, James Cameron)^filmed.arg2(e,Titanic)^filmed.in(e, 1997)
�e.filmed.arg1(e, /m/03 gd) ^ filmed.arg2(e, /m/0dr 4) ^ filmed.in(e, 1997)
Motivation�e.filmed.arg1(e, James Cameron)^filmed.arg2(e,Titanic)^filmed.in(e, 1997)
�e.filmed.arg1(e, /m/03 gd) ^ filmed.arg2(e, /m/0dr 4) ^ filmed.in(e, 1997)
Motivation�e.filmed.arg1(e, James Cameron)^filmed.arg2(e,Titanic)^filmed.in(e, 1997)
�e.BEHIND THE SCENES.Artist(e, /m/03 gd)^BEHIND THE SCENES.Production(e, /m/0dr 4)^BEHIND THE SCENES.Time(e, 1997)
�e.BEHIND THE SCENES.Artist(e, /m/03 gd)^BEHIND THE SCENES.Production(e, /m/0dr 4)^BEHIND THE SCENES.Time(e, 1997)
FrameNet
Applications ofFrame-Semantic Parsing
Stance Classification
• Frame Semantics for Stance ClassificationHasan and Ng (CoNLL 2013)
• Two sided debates in an online forum
• Classification of stance
• Improvement over a baseline that uses bag of words and dependencies
25
Dialog Systems
• Unsupervised Induction and Filling of Semantic Slots for Spoken Dialogue Systems Using Frame-Semantic ParsingChen, Wang and Rudnicky (ASRU 2013)
• Annotation of dialog transcripts with frame-semantic structures
• Uses only a subset of frames
• Uses these annotations for slot induction
26
Stock Price Movement
• Semantic Frames to Predict Stock Price MovementXie et al. (ACL 2013)
• Predict the change in stock price from financial news
• Lots of features along with features based on frames and roles
• Shows improvements over other features
27
Summarization
• Generating Automated Meeting SummariesThomas Kleinbauer (PhD thesis, Saarland University)
• Part of a large system for generating meeting summaries
28
Outline
• Why should we build statistical models for frame semantics?
• Overview of statistical methods
• Future directions
29
Structure of Lexicon and Data
PLACINGAgentCause
Goal
ThemeArea
Time
Structure of Lexicon and Data
PLACINGAgentCause
Goal
ThemeArea
Time
frame
Structure of Lexicon and Data
PLACINGAgentCause
Goal
ThemeArea
Time
roles
frame
Structure of Lexicon and Data
PLACINGAgentCause
Goal
ThemeArea
Time
core roles
non-core roles
frame
Structure of Lexicon and Data
PLACINGAgentCause
Goal
ThemeArea
Time
excludes relationship
core roles
non-core roles
frame
Structure of Lexicon and Data
PLACINGAgentCause
Goal
ThemeArea
Time
excludes relationship
core roles
non-core roles
frame
archive.V, arrange.V, bag.V, bestow.V bin.V
predicates
PLACINGAgentCause
Goal
ThemeArea
Time
DISPERSAL
AgentCause
IndividualsDistance
Time
TRANSITIVE_ACTIONAgentCause
Patient
EventPlace
Time
INSTALLINGAgent
Component
Fixed_locationArea
Time
STORINGAgentLocation
ThemeArea
Time
STOREPossessorResource
SupplyDescriptor
Structure of Lexicon and Data
PLACINGAgentCause
Goal
ThemeArea
Time
DISPERSAL
AgentCause
IndividualsDistance
Time
TRANSITIVE_ACTIONAgentCause
Patient
EventPlace
Time
INSTALLINGAgent
Component
Fixed_locationArea
Time
STORINGAgentLocation
ThemeArea
Time
STOREPossessorResource
SupplyDescriptor
Structure of Lexicon and Data
PLACINGAgentCause
Goal
ThemeArea
Time
DISPERSAL
AgentCause
IndividualsDistance
Time
TRANSITIVE_ACTIONAgentCause
Patient
EventPlace
Time
INSTALLINGAgent
Component
Fixed_locationArea
Time
STORINGAgentLocation
ThemeArea
Time
STOREPossessorResource
SupplyDescriptor
Structure of Lexicon and Datainheritance
used by
Datasets
Benchmark Dataset(SemEval 2007)
665 frames720 role labels
8.4K unique predicate types
Training set:2.2K sentences
11.2K predicate tokens
Test set:120 sentences
1. 1K predicate tokens
LTH Frame-Semantic ParserJohansson and Nugues (2007)
Frame Identification Argument Filtering Argument Labeling
40
LTH Frame-Semantic ParserJohansson and Nugues (2007)
Frame Identification Argument Filtering Argument Labeling
41
LTH Frame-Semantic ParserJohansson and Nugues (2007)
ambiguous
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
LTH Frame-Semantic ParserJohansson and Nugues (2007)
Find the best among all frames
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
LTH Frame-Semantic ParserJohansson and Nugues (2007)
Taken from an SVM classifier trained on
ambiguous predicates
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
LTH Frame-Semantic ParserJohansson and Nugues (2007)
To increase coverage, potential predicates were extracted from WordNet and automatically frame labels were selected for
them.
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
Frame Identification Accuracy
50.0
61.3
72.5
83.8
95.0
LTH
57.3
F-Measure
LTH Frame-Semantic ParserJohansson and Nugues (2007)
LTH Frame-Semantic ParserJohansson and Nugues (2007)
Frame Identification Argument Filtering Argument Labeling
47
Argument Filtering
Bengal ’s massive stock of food was reduced to nothing
STORE
massive stock
ø
Argument Filtering
Bengal ’s massive stock of food was reduced to nothing
STORE
massive stock
ø
Bengal ’s Bengal massive stock of food
food massive Bengal ’s massive to nothing
to of ’s
Potential Arguments
Argument Filtering
Bengal ’s massive stock of food was reduced to nothing
STORE
massive stock
ø
Bengal ’s Bengal massive stock of food
food massive Bengal ’s massive to nothing
to of ’s
Potential ArgumentsBinary SVM Classification
LTH Frame-Semantic ParserJohansson and Nugues (2007)
Frame Identification Argument Filtering Argument Labeling
50
Argument Filtering
Bengal ’s massive stock of food was reduced to nothing
STORE
massive stock
ø
Multiclass SVM Classification
Argument Filtering
Bengal ’s massive stock of food was reduced to nothing
STORE
massive stock
ø
Bengal ’s Bengal massive stock of food
food massive Bengal ’s massive to nothing
to of ’s
Potential ArgumentsMulticlass SVM Classification
Argument Filtering
Bengal ’s massive stock of food was reduced to nothing
STORE
massive stock
ø
Bengal ’s Bengal massive stock of food
food massive Bengal ’s massive to nothing
to of ’s
Potential ArgumentsMulticlass SVM Classification
Possessor Resource
Descriptorø
Full Frame-Semantic Structure Prediction
35.0
43.8
52.5
61.3
70.0
LTH
44.4
F-Measure
LTH Frame-Semantic ParserJohansson and Nugues (2007)
SEMAFORDas, Chen, Martins, Schneider, Smith (2014)
Frame Identification Argument Identification
54
SEMAFORDas, Chen, Martins, Schneider, Smith (2014)
Frame Identification Argument Identification
55
SEMAFOR: Frame Identification
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
SEMAFOR: Frame Identification
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
Logistic regression with a latent variable
SEMAFOR: Frame Identification
Logistic regression with a latent variable
SEMAFOR: Frame Identification
Logistic regression with a latent variable
Predicates evoking a frame in supervised data, e.g.cargo.N, inventory.N, reserve.N, stockpile.N, store.N, supply.N
evoke STORE
SEMAFOR: Frame Identification
STORE stock.N
stockpile.N
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
SEMAFOR: Frame Identification
STORE stock.N
stockpile.N
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
LexSem = {synonym}
SEMAFOR: Frame Identification
STORE stock.N
stockpile.N
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
LexSem = {synonym}
If STORE
stockpile.Nsynonym LexSem
SEMAFOR: Frame Identification
STORE stock.N
stockpile.N
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
LexSem = {synonym}
If STORE
stockpile.Nsynonym LexSem
comes from WordNet!
SEMAFOR: Frame Identification
Datasets
New Data(FrameNet 1.5, 2010)
877 frames1068 role labels
9.3K unique predicate types
Training set:3.3K sentences
19.6K predicate tokens
Test set:2420 sentences
4.5K predicate tokens
Benchmark Dataset(SemEval 2007)
665 frames720 role labels
8.4K unique predicate types
Training set:2.2K sentences
11.2K predicate tokens
Test set:120 sentences
1. 1K predicate tokens
New Data(FrameNet 1.5, 2010)
877 frames1068 role labels
9.3K unique predicate types
Training set:3.3K sentences
19.6K predicate tokens
Test set:2420 sentences
4.5K predicate tokens
Benchmark Dataset(SemEval 2007)
665 frames720 role labels
8.4K unique predicate types
Training set:2.2K sentences
11.2K predicate tokens
Test set:120 sentences
1. 1K predicate tokens
Datasets
SEMAFOR: Frame Identification
ResultsBenchmark
50.0
61.3
72.5
83.8
95.0
LTH SEMAFOR
6157.3
F-Measure
New Data
log-linear
ResultsBenchmark
50.0
61.3
72.5
83.8
95.0
LTH SEMAFOR
6157.3
F-Measure
New Data
log-linear
auto predicates
SEMAFOR: Frame Identification
ResultsBenchmark
50.0
61.3
72.5
83.8
95.0
LTH SEMAFOR
6157.3
F-Measure
New Data
log-linear
auto predicates
50.0
61.3
72.5
83.8
95.0
SEMAFOR
83.0
Accuracy
log-linear
gold predicates
SEMAFOR: Frame Identification
20.0
38.8
57.5
76.3
95.0
All Predicates
83.0
Accuracy
20.0
38.8
57.5
76.3
95.0
Unknown Predicates
23.1
Accuracy
Frame Identification
SEMAFOR: Frame Identification
SEMAFOR: Handling Unknown Predicates
Knowledge of only 9,263 predicates in supervised data
Knowledge of only 9,263 predicates in supervised data
However, English has lot more potential predicates(~65,000 in newswire English)
SEMAFOR: Handling Unknown Predicates
Knowledge of only 9,263 predicates in supervised data
However, English has lot more potential predicates(~65,000 in newswire English)
Lexicon expansion using graph-based semi-supervised learning
SEMAFOR: Handling Unknown Predicates
How can label propagation help?
Example Graph
Seed predicates
Example Graph
Seed predicatesUnseen predicates
Example Graph
Seed predicatesUnseen predicates
Graph Propagation
Example Graph
Seed predicatesUnseen predicates
Graph Propagation
Example Graph
Seed predicatesUnseen predicates
Graph Propagation
Continues till convergence...
15.0
28.8
42.5
56.3
70.0
Supervised Self-Training Graph-Based
42.7
18.923.1
Accuracy
Frame Identification
SEMAFOR: Unknown Predicates
SEMAFORDas, Chen, Martins, Schneider, Smith (2014)
Frame Identification Argument Identification
81
SEMAFOR: Argument Identification
Bengal ’s massive stock of food was reduced to nothing
STORE
Bengal ’s massive stock of food was reduced to nothing
STORE
Possessor
Resource
Supply
Use
Descriptor
SEMAFOR: Argument Identification
stock
STORE
Possessor
Resource
Supply
Use
Descriptor
Bengal ’s
Bengal
massive stock
of food
food
massive
Bengal ’s massive
massive stock
ø
SEMAFOR: Argument Identification
stock
STORE
Possessor
Resource
Supply
Use
Descriptor
Bengal ’s
Bengal
massive stock
of food
food
massive
Bengal ’s massive
massive stock
ø
SEMAFOR: Argument Identification
stock
STORE
Possessor
Resource
Supply
Use
Descriptor
Bengal ’s
Bengal
massive stock
of food
food
massive
Bengal ’s massive
massive stock
ø
Violates overlap constraints
SEMAFOR: Argument Identification
Other types of structural constraints
PLACINGAgentCause
Goal
ThemeArea
Time
Mutual exclusion constraint
archive.V, arrange.V, bag.V, bestow.V bin.V
SEMAFOR: Argument Identification
Other types of structural constraints
PLACINGAgentCause
Goal
ThemeArea
Time
Mutual exclusion constraint
archive.V, arrange.V, bag.V, bestow.V bin.V
If an agent places something, there cannot be a cause role in the sentence
SEMAFOR: Argument Identification
Other types of structural constraints
PLACINGAgentCause
Goal
ThemeArea
Time
Mutual exclusion constraint
archive.V, arrange.V, bag.V, bestow.V bin.V
The waiter placed food on the table.
In Kabul, hauling water put food on the table.Cause
Agent
SEMAFOR: Argument Identification
Other types of structural constraints
SIMILARITYDimension
Differentiating_fact
Entity_1
Entity_2
Degree
Requires constraint
difference.N, resemble.V,
unliike.A, vary.V
SEMAFOR: Argument Identification
Other types of structural constraints
SIMILARITYDimension
Differentiating_fact
Entity_1
Entity_2
Degree
Requires constraint
difference.N, resemble.V,
unliike.A, vary.V
A mulberry resembles a loganberry.
second entity
first entity
SEMAFOR: Argument Identification
Other types of structural constraints
SIMILARITYDimension
Differentiating_fact
Entity_1
Entity_2
Degree
Requires constraint
difference.N, resemble.V,
unliike.A, vary.V
A mulberry resembles.!
SEMAFOR: Argument Identification
stock
STORE
Possessor
Resource
Supply
Use
Descriptor
Bengal ’s
Bengal
massive stock
of food
food
massive
Bengal ’s massive
massive stock
ø
A constrained optimization
problem
SEMAFOR: Argument Identification
stock
STORE
Possessor
Resource
Supply
Use
Descriptor
Bengal ’s
Bengal
massive stock
of food
food
massive
Bengal ’s massive
massive stock
ø
SEMAFOR: Argument Identification
stock
STORE
Possessor
Resource
Supply
Use
Descriptor
Bengal ’s
Bengal
massive stock
of food
food
massive
Bengal ’s massive
massive stock
ø
SEMAFOR: Argument Identification
A constrained optimization problem
SEMAFOR: Argument Identification
A constrained optimization problem
a binary variable for each role, span tuple
SEMAFOR: Argument Identification
A constrained optimization problem
a binary vector for all role, span tuples
SEMAFOR: Argument Identification
A constrained optimization problem
SEMAFOR: Argument Identification
A constrained optimization problem
SEMAFOR: Argument Identification
A constrained optimization problem
Uniqueness
SEMAFOR: Argument Identification
A constrained optimization problem
Prevents overlap
SEMAFOR: Argument Identification
A constrained optimization problem
more structural constraints
An integer linear program (ILP)
SEMAFOR: Argument Identification
A constrained optimization problem
more structural constraints
An integer linear program (ILP)
Punyakanok, Roth and Yih
(2008)
SEMAFOR: Argument Identification
A constrained optimization problem
more structural constraints
An integer linear program (ILP)
Often, very slow solutions
SEMAFOR: Argument Identification
A constrained optimization problem
more structural constraints
An integer linear program (ILP)
Fast ILP solvers proprietary
SEMAFOR: Argument Identification
A constrained optimization problem
more structural constraints
An integer linear program (ILP)
Dual Decomposition
SEMAFOR: Argument Identification
SEMAFOR: Frame-Semantic Parsing
Final Results
Benchmark
35.0
43.8
52.5
61.3
70.0
LTH SEMAFOR
46.542.0
F-Measure
New Data
SEMAFOR: Frame-Semantic Parsing
Final Results
Benchmark
35.0
43.8
52.5
61.3
70.0
LTH SEMAFOR
46.542.0
F-Measure
New Data
auto predicates
SEMAFOR: Frame-Semantic Parsing
Final Results
Benchmark
35.0
43.8
52.5
61.3
70.0
LTH SEMAFOR
46.542.0
F-Measure
New Data
auto predicates
35.0
43.8
52.5
61.3
70.0
SEMAFOR
64.5
F-Measure
gold predicates
Hermann, Das, Weston and GanchevACL 2014
111
112
Frame Identification with Embeddings
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
112
Frame Identification with Embeddings
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
113
Frame Identification with Embeddings
Discrete lexical features
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
114
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
Frame Identification with Embeddings
Syntactic context words connected via a set of
dependency paths
amod
; massiveprep pobj ; food
nsubjpass auxpass ; was
... ; ...
115
Bengal ’s massive stock of food was reduced to nothingN X A N ADP N V V ADP N
Frame Identification with Embeddings
amod
; massiveprep pobj ; food
nsubjpass auxpass ; was
amod
;prep pobj ;
nsubjpass auxpass ;
Replace context words with off-the-shelf word
embeddings
... ; ... ... ; ...
116
Frame Identification with Embeddingsamod
; massiveprep pobj ; food
nsubjpass auxpass ; was
amod
;prep pobj ;
nsubjpass auxpass ;
... ; ... ... ; ...
amod nsubj dobj>prep>pobjp<nsubjpass>auxpass...
Input sparse embedding vector with context blocks
117
Frame Identification with Embeddings
Frame instance space
N ⇥ Rd
117
Frame Identification with Embeddings
Frame instance space
N ⇥ Rd
Joint SpaceRm
117
Frame Identification with Embeddings
Frame instance space
N ⇥ Rd
Joint SpaceRm
Frame Instance MapM : Rd ! Rm
117
Frame Identification with Embeddings
Frame instance space
N ⇥ Rd
Joint SpaceRm
Frame Instance MapM : Rd ! Rm
Set of FrameNet labels
STORESTORING
STINGINESS...
...
117
Frame Identification with Embeddings
Frame instance space
N ⇥ Rd
Joint SpaceRm
Frame Instance MapM : Rd ! Rm
Set of FrameNet labels
STORESTORING
STINGINESS...
...
Y 2 RF⇥mLabel matrix
117
Frame Identification with Embeddings
Frame instance space
N ⇥ Rd
Joint SpaceRm
Frame Instance MapM : Rd ! Rm
Set of FrameNet labels
STORESTORING
STINGINESS...
...
Y 2 RF⇥mLabel matrix
learned learned
118
Frame Identification with Embeddings
118
Frame Identification with Embeddings
frame instances
118
Frame Identification with Embeddings
frame instancesframe labels
119
Frame Identification with Embeddings
frame instancesframe labels
?
test predicate
119
Frame Identification with Embeddings
frame instancesframe labels
?
test predicate
120
Frame Identification with Embeddings
frame instancesframe labels
?
test predicate
120
Frame Identification with Embeddings
frame instancesframe labels
?
121
Frame Identification with Embeddings
frame instancesframe labels
?
15.0
28.8
42.5
56.3
70.0
Supervised Self-Training Graph-Based Embeddings
46.1542.7
18.923.1
Accuracy
Frame Identification
Results on Unknown Predicates
SEMAFOR
75.0
78.8
82.5
86.3
90.0
Supervised Self-Training Graph-Based Embeddings
86.49
83.682.3
83.0
Accuracy
Frame Identification
Results on All Predicates
SEMAFOR
60.0
62.5
65.0
67.5
70.0
Supervised Graph-Based Embeddings
68.7
64.564.1
F-Score
Frame-Semantic Parsing
Final Results
SEMAFOR
Outline
• Why should we build statistical models for frame semantics?
• Overview of statistical methods
• Future directions
125
Better Models
• Very little research on argument identification
• More non-local features
• Using distributed representations
• Generalization using PropBank resources
126
Data• Number of FrameNet annotated sentences ~30
times less than PropBank/Ontonotes.
• Number of argument labels ~30 times more
• To make systems usable, we need annotations
• inter-annotator agreement studies
• annotation guidelines127
Custom FrameNets
• Is a general FrameNet lexicon useful?
• often, FrameNet frames are too general or too specific
• is it possible to quickly build customized FrameNet lexicons for applications?
• is it possible to use PropBank-style frames to induce FrameNet-style frames?
128
Conclusions
• Lot of exciting work in predicate-argument structure prediction
• Semi-supervised methods improve coverage
• Systems trained on small amounts of FrameNet-style data shown to be useful
• More annotations will result in usable systems
129
Thank You
130