Annotation The three volume set LNAI 4692, LNAI 4693, and LNAI 4694, constitute the refereed proceedings of the 11th International Conference on Knowledge-Based Intelligent Information and Engineering Systems, KES 2007, held in Vietri sul Mare, Italy, September 12-14, 2007. The 409 revised papers presented were carefully reviewed and selected from about 1203 submissions. The papers present a wealth of original research results from the field of intelligent information processing in the broadest sense; topics covered in the first volume are artificial neural networks and connectionists systems, fuzzy and neuro-fuzzy systems, evolutionary computation, machine learning and classical AI, agent systems, knowledge based and expert systems, hybrid intelligent systems, miscellaneous intelligent algorithms, intelligent vision and image processing, knowledge management and ontologies, Web intelligence, multimedia, e-learning and teaching, intelligent signal processing, control and robotics, other intelligent systems applications, papers of the experience management and engineering workshop, industrial applications of intelligent systems, as well as information engineering and applications in ubiquotous computing environments.