Ellen K. Cromley, PhD, is Professor of Geography at the University of Connecticut, Storrs, Connecticut, and is affiliated with the Department of Community Medicine and Health Care, University of Connecticut Health Center, Farmington, Connecticut. Her research is primarily concerned with geographical patterns of health and disease, health facility location, and GIS design to support public health surveillance and intervention programs. She has published in geography, epidemiology, public health, and health services journals. Sara L. McLafferty, PhD, is Professor of Geography at the Universi...