The Effectiveness of Query Expansion when searching for Health related Content: InfoLab at CLEF eHealth 2016

In this paper we describe the participation of InfoLab in the patient-centred information retrieval task of the CLEF eHealth 2016 lab. We analyse the performance of several query expansion strategies using different sources of terms and different methods to select the terms to be added to the original query. One of the strategies uses pseudo relevance feedback for term selection. The other strategies use external sources such as Wikipedia articles and definitions from the UMLS Metathesaurus for term selection. In the end, readability metrics such as SMOG, FOG and Flesch-Kincaid were used to re-rank the documents retrieved using the expanded queries. As the relevance and readability assessments are not available we can’t make any conclusion regarding the results of our approaches.