Improved biomedical document retrieval system with PubMed term statistics and expansions

摘要

Large biomedical abstract databases such as MEDLINE enable users to search for large bodies of biomedical knowledge quickly. In this study, we describe a new framework to improve the performance of MEDLINE document retrieval. We first analysed and built a normalized term frequency distributions for 1.8 million terms by sampling from 1,500,000 MEDLINE abstracts. Then, we developed a statistical model to identify significantly observed terms ('gists') in a document as additional document keywords to help improve document retrieval precisions. To improve document recalls, we integrated several biological ontologies that can expand user queries with semantically compatible terms. The framework was implemented in Oracle 10g.