Directional Distributional Similarity for Lexical Expansion

Distributional word similarity is most commonly perceived as a symmetric relation. Yet, one of its major applications is lexical expansion, which is generally asymmetric. This paper investigates the nature of directional (asymmetric) similarity measures, which aim to quantify distributional feature inclusion. We identify desired properties of such measures, specify a particular one based on averaged precision, and demonstrate the empirical benefit of directional measures for expansion.

• Type: Journal
• Year: 2009
• Where: ACL
• Authors: Lili Kotlerman, Ido Dagan, Idan Szpektor, Maayan Zhitomirsky-Geffet
• Keywords: ACL 2009, Computational Linguistics, Distributional Feature Inclusion, Distributional Word, Symmetric Relation