He holds a Ph.D. in Sociology from Rhodes University, an M.A. in Applied Social Research from the University of Michigan and an M.Soc.Sc. from the University of Cape Town. He has taught a number of graduate classes on survey design and analysis. He has consulted for numerous clients, both private and public, on all aspects of survey design and data collection. His current research focuses on nonresponse, the role of the interviewer, and computer assisted survey data collection (including CATI, CAPI, audio-CASI, and Web surveys). He is engaged in several projects on the design and evaluation of Web surveys. He is the co-author (with Robert Groves) of Nonresponse in Household Interview Surveys (Wiley, 1998), and chief editor of Computer Assisted Survey Information Collection (Wiley, 1998).