From CLEF to TrebleCLEF: the Evolution of the Cross-Language Evaluation Forum

The Cross-Language Evaluation Forum (CLEF) has been running for nearly ten years now; the aim of this paper is to provide a critical assessment of the results achieved so far. In the first part of the paper, we pro- vide a brief overview of the entire activity and sum- marise the main achievements; in the second part, we focus our attention on the Ad Hoc track with the aim of showing how the results of evaluation can be exploited to increase understanding of the many issues involved in multilingual retrieval system development. In the final part, we outline our main ideas for the future of CLEF.