Paper: Positional Language Models for Clinical Information Retrieval

ACL ID D10-1011
Title Positional Language Models for Clinical Information Retrieval
Venue Conference on Empirical Methods in Natural Language Processing
Session Main Conference
Year 2010

The PECO framework is a knowledge repre- sentation for formulating clinical questions. Queries are decomposed into four aspects, which are Patient-Problem (P), Exposure (E), Comparison (C) and Outcome (O). However, no test collection is available to evaluate such framework in information retrieval. In this work, we first present the construction of a large test collection extracted from system- atic literature reviews. We then describe an analysis of the distribution of PECO elements throughout the relevant documents and pro- pose a language modeling approach that uses these distributions as a weighting strategy. In our experiments carried out on a collection of 1.5 million documents and 423 queries, our method was found to lead to an improvement of 28% in MAP and 50% in P@5, as com- pared...