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Title:The semantics of role labeling
Author(s):Srikumar, Vivek
Director of Research:Roth, Dan
Doctoral Committee Chair(s):Roth, Dan
Doctoral Committee Member(s):DeJong, Gerald F.; Hockenmaier, Julia C.; Palmer, Martha
Department / Program:Computer Science
Discipline:Computer Science
Degree Granting Institution:University of Illinois at Urbana-Champaign
Degree:Ph.D.
Genre:Dissertation
Subject(s):Natural Language Processing
Machine Learning
Semantic Role Labeling
Text Processing
Structured Learning
Structured Inference
Semantic Relations
Abstract:The problem of ascribing a semantic representation to text is an important one that can help text understanding problems like textual entailment. In this thesis, we address the problem of assigning a shallow semantic representation to text. This problem is traditionally studied in the context of verbs and their nominalizations. We propose to extend the task to go beyond verbs and nominalizations to include other linguistic constructions such as commas and prepositions We develop an ontology of predicate-argument relations that commas and prepositions express in text. Just like the verb and nominal semantic role labeling schemes, the relations we propose are domain independent. For these two classes of phenomena, we introduce new corpora where these relations are annotated. From the machine learning perspective, learning to predicting these relations is a structured learning problem. However, we only have the small (for commas) or partially annotated (for prepositions) datasets. To predict the new relations, we show that using linguistic knowledge and information about output structure can bias the learning to build robust models. Finally, we observe that the relations expressed by the various phenomena interact with each other by constraining each others' output. We show that we can take advantage of these inter-dependencies by enforcing coherence between their predictions. By constraining inference using linguistic knowledge, we can improve relation prediction performance.
Issue Date:2013-05-24
URI:http://hdl.handle.net/2142/44359
Rights Information:Copyright 2013 Vivek Srikumar
Date Available in IDEALS:2013-05-24
Date Deposited:2013-05


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