One of a group of geographers trained in quantitative methods in the 1960s, Lawrence A. Brown received his Ph.D. in 1965 from Northwestern University. Most of his career since then has been spent as professor at Ohio State University, which has one of the leading research and graduate programs in modern geography. Brown's early work focused on the dynamics of modern cities, and his research on intraurban migration remains among the most often cited in this broadly interdisciplinary subject. Throughout the 1970s his research focused more closely on the geographic spread of innovations. The last of the three books he produced based on this research, Innovation Diffusion: A New Perspective (1981), was particularly well received because it shifted attention from the demand for innovations to their supply. By the 1980s, Brown's work had extended to focus on the process of economic and demographic development, particularly as it relates to Latin America. He developed a paradigm for the interrelationships between migration and economic development. His current work is on the spatial aspects of settlement system evolution in Latin America.
Tom Holme (Ph.D, Rice University) is a chemistry professor at Iowa State University and Director of the ACS Examinations Institute. He is active in both computational chemistry and chemical education research and has been involved with the general chemistry for engineers course at both Iowa State and the University of Wisconsin - Milwaukee. Some of his recent publications include: "Designing Chemistry Practice Exams for Enhanced Benefits: An Instrument for Comparing Performance and Mental Effort Measures," (Karen Knaus, Kristen Murphy and Thomas Holme), Journal of Chemical Education, 2009, in press; "Nanoscience Items for Standardized Exams in the Undergraduate Chemistry Curriculum" (Thomas Holme), in Nanoscale Science and Engineering Education: Issues, Trends and Future Directions, ed., A.E. Sweeny & S. Seal, American Scientific Publishers, Stevenson Ranch, CA, 2008; and "Assessing Problem-solving Strategies in Chemistry Using the IMMEX System" in Proceedings of the National STEM Assessment Conference, eds. D. Deeds & B. Callen, National Science Foundation, Washington, DC, 2008.