Figure 1

QuExT query expansion procedure. Query expansion and document ranking procedure: a) gene names in the query are converted to internal identifiers; b) the different gene name synonyms and related concepts for each gene are used to expand the user query; c) the index is searched for each term in the expanded query; d) resulting documents and scores are kept in separate lists (one for each concept class); e) results are assembled using the user-defined weights for each concept and the final results are normalized in relation to the highest score.