The European Conference on Information Retrieval Research, now in its 25th “Silver Jubilee” edition, was initiallyestablished bythe Information Retrieval Specialist Group of the British Computer Society(BCS-IRSG) under the name “Annual Colloquium on Information Retrieval Research,” and was always held in the United Kingdom until 1997. Since 1998 the location of the colloquium has alternated between the United Kingdom and the rest of Europe, in order to re?ect the growing European orientation of the event. For the same reason, in 2001 the event was renamed “European Annual Colloquium on Information Retrieval Research.” Since 2002, the proceedings of the Colloquium have been published bySpringer-Verlag in their Lecture Notes in Computer Science series. In 2003 BCS-IRSG decided to rename the event “European Conference on Information Retrieval Research,” in order to re?ect what the event had slowly turned into, i.e., a full-blown conference with a European program committee, strong peer reviewing, and a (mostly) European audience. However, ECIR still retains the strong student focus that has characterized the Colloquia since their inception: student fees are kept particularlylow, a s- dent travel grant program is available in order to encourage students to attend the conference (and encourage student authors to present their papers pers- ally), and a Best Student Paper Award is assigned (conversely, ECIR has no best paper award).
Lecture Notes in Computer Science Edited by G. Goos, J. Hartmanis, and J. van Leeuwen
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Fabrizio Sebastiani (Ed.)
Advances in Information Retrieval 25th European Conference on IR Research, ECIR 2003 Pisa, Italy, April 14-16, 2003 Proceedings
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Series Editors Gerhard Goos, Karlsruhe University, Germany Juris Hartmanis, Cornell University, NY, USA Jan van Leeuwen, Utrecht University, The Netherlands Volume Editor Fabrizio Sebastiani Istituto di Scienza e Tecnologie dell’Informazione Consiglio Nazionale delle Ricerche Via Giuseppe Moruzzi, 1, 56124 Pisa, Italy E-mail:
[email protected] Cataloging-in-Publication Data applied for A catalog record for this book is available from the Library of Congress. Bibliographic information published by Die Deutsche Bibliothek Die Deutsche Bibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data is available in the Internet at .
CR Subject Classification (1998): H.3, H.2, I.2.3, I.2.6, H.4, H.5.4, I.7 ISSN 0302-9743 ISBN 3-540-01274-5 Springer-Verlag Berlin Heidelberg New York This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, re-use of illustrations, recitation, broadcasting, reproduction on microfilms or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under the German Copyright Law. Springer-Verlag Berlin Heidelberg New York a member of BertelsmannSpringer Science+Business Media GmbH http://www.springer.de © Springer-Verlag Berlin Heidelberg 2003 Printed in Germany Typesetting: Camera-ready by author, data conversion by DA-TeX Gerd Blumenstein Printed on acid-free paper SPIN: 10924907 06/3142 543210
Preface
The European Conference on Information Retrieval Research, now in its 25th “Silver Jubilee” edition, was initially established by the Info