CLEF 2003 – Overview of Results

The fourth CLEF campaign, CLEF 2003, was marked by a large increase in the number of experiments submitted by participants. More complex tasks (multilingual retrieval on documents written in eight different languages), new document sources, and a new, ninth document language, Russian, led to a wide variety of work being conducted in this campaign. This paper discusses the tracks that have been offered since the beginnings of CLEF, and that still have the highest participation, i.e. the ad-hoc and domain-specific tracks. Collectively, these tracks attracted 33 participating groups who submitted more than 400 experiments. This overview gives a brief description of the tracks and tasks, and summarizes the principal research results. A discussion of the validity of the results, in terms of the completeness of the relevance assessments used in the test collection and of the statistical significance of some of the results, is also given.