Acknowledgments

This work was partially supported by BUAP-VIEP 3/G/ING/05, R2D2 (CICYTTIC 2003-07158-C04-03), ICT EU-India (ALA/95/23/2003/077-054), and Generalitat Valenciana Grant (CTESIN/2005/12). We would like also thank the CLEF 2005 organising committe (This work is a revised version of the paper ``TPIRS: A System for Document Indexing Reduction at WebCLEF'').