The papers in this volume are the refereed application papers presented at AI-2003, the Twenty-third SGAI International Conference on Innovative Techniques and Applications of Artificial Intelligence, held in Cambridge in December 2003. The papers present new and innovative developments in the field, divided into sections on Personalisation, E-Commerce and Resource Management, Hazard Prediction, Fault Diagnosis and Design, Medical and Social Services and Image Recognition, Knowledge Bases and Attribute Selection. This is the eleventh volume in the Applications and Innovations series. The series serves as a key reference on the use of AI Technology to enable organisations to solve complex problems and gain significant business benefits. The Technical Stream papers are published as a companion volume under the title Research and Development in Intelligent Systems XX.