PASCAL - Pattern Analysis, Statistical Modelling and Computational Learning

Definition and Analysis of Intermediate Entailment Levels
Roy Bar Haim, Idan Szpektor and Oren Glickman
In: Empirical Modeling of Semantic Equivalence and Entailment Workshop at the Annual Meeting of the Association of Computational Linguistics (ACL 2005), 30 June 2005, Ann Arbor, Michigan, USA.


In this paper we define two intermediate models of textual entailment, which correspond to lexical and lexical-syntactic levels of representation. We manually annotated a sample from the RTE dataset according to each model, compared the outcome for the two models, and explored how well they approximate the notion of entailment. We show that the lexicalsyntactic model outperforms the lexical model, mainly due to a much lower rate of false-positives, but both models fail to achieve high recall. Our analysis also shows that paraphrases stand out as a dominant contributor to the entailment task. We suggest that our models and annotation methods can serve as an evaluation scheme for entailment at these levels.

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EPrint Type:Conference or Workshop Item (Paper)
Project Keyword:Project Keyword UNSPECIFIED
Subjects:Natural Language Processing
ID Code:1431
Deposited By:Idan Szpektor
Deposited On:28 November 2005