Book excerpt: Elements of Spatial Data Quality outlines the need and suggests potential categories for the content of a comprehensive statement of data quality that must be imbedded in the metadata that accompanies the transfer of a digital spatial data file or is available in a separate metadata catalog. Members of the International Cartographic Association's Commission on Spatial Data Quality have identified seven elements of data quality: positional accuracy, attribute accuracy, completeness, logical consistency, lineage, semantic accuracy and temporal information. In the book the authors describe: components of each data quality element, possible metrics that can be used to measure the quality of each criteria, possible testing and rating schemes, and how these parameters might differ from a producer or user point of view. Finally no volume of this nature would be complete without a chapter devoted to necessary future research in this subject area. The chapter points out areas in need of further investigation and speculates about the use and transfer of digital spatial data in tomorrow's electronic world and at developments in presenting specified data quality information in a visualization. This book will be of interest to all of those individuals involved in geographical information systems and spatial data handling.