Paraphrasing Adaptation for Web Search Ranking.

Mismatch between queries and documents is a key issue for the web search task. In order to narrow down such mismatch, in this paper, we present an in-depth investigation on adapting a paraphrasing technique to web search from three aspects: a search-oriented paraphrasing model; an NDCG-based parameter optimization algorithm; an enhanced ranking model leveraging augmented features computed on paraphrases of original queries. Experiments performed on the large scale query-document data set show that, the search performance can be significantly improved, with +3.28% and +1.14% NDCG gains on dev and test sets respectively.