This book constitutes the refereed proceedings of the 9th International Conference on Spatial Information Theory, COSIT 2007, held in Melbourne, Australia, in September 2007.

The 27 revised full papers presented were carefully reviewed and selected from 102 submissions. The papers are organized in topical sections on cultural studies, semantics, similarity, mapping and representation, perception and cognition, reasoning and algorithms, navigation and landmarks, as well as uncertainty and imperfection.