The papers in this volume are the refereed technical papers presented at AI-2007, the Twenty-seventh SGAI International Conference on Innovative Techniques and Applications of Artificial Intelligence, held in Cambridge in December 2007. They present new and innovative developments in the field, divided into sections on Constraint Satisfaction, AI Techniques, Data Mining and Machine Learning, Multi-Agent Systems, Data Mining and Knowledge Acquisition and Management, followed by the text of short papers presented as posters at the conference. This is the twenty-fourth volume in the Research and Development series. The series is essential reading for those who wish to keep up to date with developments in this important field. The Application Stream papers are published as a companion volume under the title Applications and Innovations in Intelligent Systems XV.