The German Conference on Arti?cial Intelligence is a traditional and unique yearly event which brings together the German AI community and an increasing numberofinternationalguests.WhilenotasoldasIJCAI(which?rsttookplace in 1969), KI2003 marks a tradition which o?cially began in 1975 with a wor- hop of the working group "Kunstlic .. he Intelligenz" of GI. Actually, there was one important AI conference in Germany before this, the "Fachtagung Cognitive Verfahren und Systeme" (Cognitive Methods and Systems) held in Hamburg in April 1973. Thisvolumecontainstheproceedingsofthe26thAnnualGermanConference on Arti?cial Intelligence. For the technical program we had 90 submissions from 22 countries. Out of these contributions 18 papers were accepted for oral pres- tation and 24 papers for poster presentation. The acceptance criteria were set to meet high international standards. Poster presenters were given the additional opportunity to summarize their papers in three minute spotlight presentations. Oral, spotlight as well as the poster presentations were then scheduled in an interesting conference program, summarized in the book you have before you.