Paper: Beyond Projectivity: Multilingual Evaluation of Constraints and Measures on Non-Projective Structures

ACL ID P07-1077
Title Beyond Projectivity: Multilingual Evaluation of Constraints and Measures on Non-Projective Structures
Venue Annual Meeting of the Association of Computational Linguistics
Session Main Conference
Year 2007
Authors

Dependency analysis of natural language has gained importance for its applicability to NLP tasks. Non-projective structures are common in dependency analysis, there- fore we need fine-grained means of describ- ing them, especially for the purposes of machine-learning oriented approaches like parsing. We present an evaluation on twelve languages which explores several constraints and measures on non-projective structures. We pursue an edge-based ap- proach concentrating on properties of in- dividual edges as opposed to properties of whole trees. In our evaluation, we include previously unreported measures taking into account levels of nodes in dependency trees. Our empirical results corroborate theoreti- cal results and show that an edge-based ap- proach using levels of nodes provides an ac...