It has increasingly become clear that functional information is necessary in addition to geometric information in explaining spatial semantics, and this book provides an excellent synthesis of developments in the literature. The authors point out that while early accounts are untenable due to their heavy reliance on geometry, more recent accounts too often merely catalogue the flaws of these systems, and do not clearly describe alternative systems that could generate a wide variety of behaviours with relatively little machinery. The authors' notion of location control is compelling in that it appears to address the concerns of recent work with the simplicity found in earlier geometry accounts. I found it a pleasure to read. - Ed Munnich, University of California, BerkeleyThis book nicely covers a wide scattering of ideas that have appeared in the literature over a great number of years, pulling them all together into a unified account. - Laura Carlson, University of Notre Dame