Accessibility in space and time: A theme in spatially integrated social science

component of social science research in the past two decades (Goodchild et al. 2000). This is mainly due to recent advances in spatial technologies (especially GIS), the availability of a massive amount of geocoded data, and the recognition that space can be a powerful integrating framework for social science disciplines. In light of the growing significance of space, location, and place in social science research, and based upon the vision that a spatial approach provides a compelling integrating framework for the social sciences, the Center for Spatially Integrated Social Science (CSISS) was established to develop unrestricted access to tools and perspectives that will advance the spatial analytic capabilities of researchers throughout the social sciences. CSISS is funded by the National Science Foundation (USA) under its program of support for infrastructure in the social and behavioral sciences. It focuses on spatial analysis as an integrating force for the social sciences and seeks to achieve its goals through six interrelated programs: learning resources, workshops, best-practice publications, place-based search methodologies, software tools development, and a virtual community (e.g. Goodchild and Janelle 2003). These programs are informed by recent advances in spatial information science, and are designed to provide infrastructure to facilitate the national dissemination of spatial perspectives across the social science disciplines. The contributors of this special issue of the Journal of Geographical Systems were the instructors of the CSISS workshop on Accessibility in Space and Time: A GIS Approach, held at the Ohio State University in July 2002. As part of the CSISS program, the workshop is based upon the premise that concepts and methods for analyzing accessibility are essential for understanding many significant social, economic, and political issues (e.g., access to jobs, healthcare, transportation, and other public facilities for different