This volume comprises contributions from different disciplines (cognitive psychology, linguistics, computer science, neuroscience) concerned with the generation of natural speech. It summarizes the outcome of a six-year long priority program funded by the German Research Foundation (DFG) that aimed at bringing together colleagues with different viewpoints but sharing a principal interest in the cognitive processes underlying language production. The result is a state-of-the-art discussion of one of the most fascinating branches of human behavior taking into account a particularly rich multidisciplinary empirical data base.

This third volume documents the results achieved within a priority program on spatial cognition funded by the German Science Foundation (DFG). The 23 revised full papers presented went through two rounds of reviewing and improvement and reflect the increased interdisciplinary cooperation in the area. The papers are organized in topical sections on routes and navigation, human memory and learning, spatial representation, and spatial reasoning.

Spatialcognitionisconcernedwiththewayshumans,animals,ormachinesthink about real or abstract space and also with the ways spatial structures can be used for reasoning. Thus, space is considered both, as an object of cognition and as ameans of cognition. Spatial cognition is an interdisciplinary research areainvolvingapproachesfromarti?cialintelligence,cognitivepsychology,ge- raphy, mathematics, biology, design, theoretical computer science, architecture, andphilosophy.Researchonspatialcognitionhasprogressedrapidlyduringthe past few years. The disciplines contributing to the ?eld have moved closer - getherandbegintospeakacommonlanguage.Theyhavefoundwaysofmerging theresearchresultsobtainedthroughdi?erentapproaches.Thisallowsfordev- oping more sophisticated hybrid approaches that overcome intrinsic limitations of the individual disciplines. Research on spatial cognition has drawn increased attention in recent years foratleastthreedi?erentreasons:(1)basicresearchdimension:thereisagr- ing awareness of the importance of spatial cognitive abilities in biological s- tems, speci?cally with respect to perception and action, to the organization of memory, and to understanding and producing natural language; (2) compu- tionaldimension:spatialrepresentationsandspatialinferencemayprovidesu- ablelimitationsto enhancethe computationale? ciencyforalargeandrelevant class of problems; (3) application dimension: a good understanding of spatial processes is essential for a wide variety of challenging application areas incl- ing Geographic Information Systems (GIS), pedestrian and vehicle navigation aids,autonomousrobots,smartgraphics,medicalsurgery,informationretrieval, virtual reality, Internet navigation, and human-computer interfaces. This is the second volume published in the framework of the Spatial Cog- tion Priority Program. It augments the results presented in Freksa et al. 1998.

Research on spatial cognition is a rapidly evolving interdisciplinary enterprise for the study of spatial representations and cognitive spatial processes, be they real or abstract, human or machine. Spatial cognition brings together a variety of - search methodologies: empirical investigations on human and animal orientation and navigation; studies of communicating spatial knowledge using language and graphical or other pictorial means; the development of formal models for r- resenting and processing spatial knowledge; and computer implementations to solve spatial problems, to simulate human or animal orientation and navigation behavior, or to reproduce spatial communication patterns. These approaches can interact in interesting and useful ways: Results from empirical studies call for formal explanations both of the underlying memory structures and of the processes operating upon them; we can develop and - plement operational computer models obeying the relationships between objects and events described by the formal models; we can empirically test the computer models under a variety of conditions, and we can compare the results to the - sults from the human or animal experiments. A disagreement between these results can provide useful indications towards the re nement of the models.

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. Also included are three excellent invited contributions by Anthony G. Cohn, Kurt Konolige, and Pat Langley. The papers are organized in topical sections on theorem proving, nonclassical logics, knowledge representation, spatial reasoning, computational linguistics, computer perception and neural nets, and on planning, diagnosis and search.

For an interdisciplinary approach to linguistics spatial concepts are of especial significance in that they represent a link between linguistic and extra-linguistic cognition. In language production spatial representations form the starting-point for a class of linearization processes; vice versa, in language reception we have delinearization processes building up mental spatial representations from linguistic structures. Such processes are subject to restrictions specific to individual languages and resting on the respective relations between the language system and the conceptual system of spatial categories and relations.

Christopher Habe!, Siegfried Kanngiesser und Gert Rickheit Das Interesse an der Kognitiven Linguistik hat in den letzten Jahren auch im deutschsprachigen Raum zugenommen. Nicht zuletzt durch die Foerderung des Schwerpunktprogramms Kognitive Linguistik von Anfang 1987 bis Ende 1995 der Deutschen Forschungsgemeinschaft (DFG) wurde eine systematische Erforschung dieses Themenkomplexes ermoeglicht. Obwohl die gefoerderten Projekte bei weitem nicht die Komplexitat dieses vielfaltigen Bereichs komplett erforschen konnten, wurden doch im Forschungszeitraum von acht Jahren wichtige Aspekte der Modeliierung und der empirischen Erforschung von Sprachproduktions-und -rezeptionsprozessen in Angriff genommen. Die Resonanz, die die beiden bisherigen Sammelbande (Felix, S. W., Kanngiesser, S. & Rickheit, G. (Hrsg.) (1990). Sprache und Wissen. Studien zur Kognitiven Linguistik. Opladen: Westdeutscher Verlag und Felix, S. W., Habel, C. & Rickheit, G. (Hrsg.) (1994). Kognitive Linguistik. Reprasentation und Prozesse. Opladen: Westdeutscher Verlag) sowie die zahlreichen Einzelver- oeffentlichungen dieses Schwerpunktes verursachten, zeigt, dass auch hierzulande die kognitionsorientierte Sprachforschung verstarkt Beachtung findet.

Ein zentraler Problemkreis der neueren KI-Forschung ist die Reprasentation des Gegenstandlichen. Insbesondere stellt sich die Frage, wie raumliche Konstellationen zu reprasentieren und zu verarbeiten sind. Primares Ziel des vorliegenden Bandes ist es, einen Uberblick uber die aktuelle Forschung im Bereich von Reprasentation und Verarbeitung raumlichen Wissens zu geben. Die Beitrage des Bandes decken das gesamte Spektrum der kognitionsorientierten KI-Forschung ab, von Arbeiten, die, in der Tradition der Kybernetik bzw. Neurophysiologie stehend, Aspekte der Raumorientierung in biologischen Systemen betreffen, uber formale Ansatze zur Bildverarbeitung und Integration von Bild- und Sprachverarbeitung, die an Fragestellungen der Theoretischen Informatik orientiert sind, bis zu Ansatzen, die die naturlichsprachliche Verarbeitung raumlicher Konstellationen durch Menschen und Maschinen betreffen. Ein weiteres Ziel des Bandes besteht darin, die Basis fur eine interdisziplinare Bearbeitung der Thematik zu schaffen. Der vorliegende Band enthalt die uberarbeiteten Fassungen von Vortragen, die bei dem Workshop "Reprasentation und Verarbeitung raumlichen Wissens" der Fachgruppe Kognition der GI im November 1988 gehalten wurden. Zusatzlich wurden einige erganzende Beitrage aufgenommen. Das Buch wird durch eine umfangreiche Bibliographie abgerundet."