This volume is a working copy of the papers presented at the 9th ASIS SIG/CR workshop on classification research, held in Washington, DC, at the ASIS Annual Meeting on Sunday 31 October 1999. The contributions printed here are working papers, and thus, not necessarily in their final form. For this reason, workshop participants and other readers are asked not to quote from the papers in this volume. After completion of the workshops, authors will have the opportunity to edit and/or revise their paper. Participants in the workshop are cordially invited to provide the authors or the editors with constructive comments to their papers. These proceedings will subsequently be published by Information Today, Inc., as an ASIS monograph entitled Advances in Classification Research: Volume JO.