The origins of this book arise from the highly successful second SIGdial Workshop on Discourse and Dialogue that was held in September 2001 in con junction with Eurospeech 2001. The original workshop proceedings consisted of 29 papers selected from 57 submissions, an exceptionally high number of submissions for a two day workshop. This book includes extended versions of 12 papers originally presented at the workshop. In addition, 4 other invited papers on major themes in discourse and dialogue research are included. There are three main themes addressed by the papers in this collection: (1)...