Yoshimasa Tsuruoka1,*, John McNaught1,2, Jun’ichi Tsujii1,2,3 and Sophia Ananiadou1,2 1 School of Computer Science, The University of Manchester, Manchester, 2 National Centre for Text Mining (NaCTeM), Manchester, UK and 3 Department of Computer Science, The University of Tokyo, Japan Received on June 3, 2007; revised on July 27, 2007; accepted on July 28, 2007 Advance Access publication August 12, 2007 Associate Editor: Jonathan Wren