This book constitutes the refereed proceedings of the 21st Annual German Conference on Artificial Intelligence, KI-97, held in Freiburg, Germany, in September 1997.The volume presents revised versions of 26 full papers and 10 posters selected from around 70 submissions from more than 15 countries.

Qualitative spatial representation and reasoning techniques.- COLBERT: A language for reactive control in Sapphira.- Machine learning for adaptive user interfaces.- Structured incremental proof planning.- Many-sorted logic in a learning theorem prover.- Rigid hypertableaux.- Minimal model generation based on E-hyper tableaux.- External analogy in inductive theorem proving.- Mechanising partiality without re-implementation.- From linear proofs to direct logic with exponentials.- Integrating an equality prover into a software development system based on type theory.- Causation and nonmonotonic temporal reasoning.- Labelled quantified modal logics.- Defining decision rules in signed horn clauses.- Modelling subjective distances.- An axiomatic approach to the spatial relations underlying left-right and in front of-behind.- Representation and processing of qualitative orientation knowledge.- A contribution to the question of authenticity of Rhesus using part-of-speech tagging.- Making objects more knowledgeable.- Constraining the acquisition of concepts by the quality of heterogeneous evidence.- Conceptualizing Adjectives.- Parsing N best trees from a word lattice.- Fast grid-based position tracking for mobile robots.- Integration of image sequence evaluation and fuzzy metric temporal logic programming.- Designing a counter: Another case study of dynamics and activation landscapes in recurrent networks.- Cooperating diagnostic expert systems to solve complex diagnosis tasks.- Tabu search vs. Random walk.- Multi-flip networks: Parallelizing genSAT.- Resource-adaptive action planning in a dialogue system for repair support.- A modal computational framework for default reasoning.- Planning diagonalization proofs.- Suffix tree automata in state space search.- Connection Cuttingfor Contraction Free Logic.- Agents in proactive environments.- Reducing lexical redundancy by augmenting conceptual knowledge.- A graphical user interface for an ECG classifier system.- Expert system in additional finishing.- Reasoning about exceptions (extended abstract).- Learning and interpretation of the layout of structured documents.