MRIM at ImageCLEF2012. From Words to Concepts: A New Counting Approach
Résumé
MRIM research group has participated in two tasks (ad-hoc image-based retrieval and case-based retrieval) of the ImageCLEF2012 Medical Retrieval track. In our contribution, we study the frequency shift problem that happens when using concepts instead of words as indexing terms. The main goal of our experiments is to check the validity of our new counting strategy of concepts (Relative Count), which is proposed as a solution to the frequency shift problem. In order to validate our new counting strategy, we compare the retrieval performance (represented by MAP) of some classical IR models using the classical counting strategy (count each concept as 1) with their performance using the new strategy. The results are promising, and using the new counting strategy shows a considerable gain in performance. We use in our experiments two supplementary resources: MetaMap as a text-to-concepts mapping tool, and UMLS as an external resource containing concepts.
Domaines
Recherche d'information [cs.IR]
Origine : Fichiers produits par l'(les) auteur(s)
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