Ronald Czaja is an associate professor of sociology and anthropology at North Carolina State University. He teaches courses in both undergraduate and graduate reserach methodology and medical sociology. His methodological reserach interests focus on sampling rare populations, response effects in surveys, and the cognitive aspects of questionnaire design. From 1969 to 1990 he worked at the Survey Research Laboratory, University of Illinois at Chicago, as project coordinator, co-head of sampling, assistant director and principal investigaor. Johnny Blair is associate director of the Survey Research Center, University of Maryland. He has conducted methodological research on cognitive aspects of proxy reporting, sampling for special or rare populations, and alternative methods for pretesting questionnaires. He has been a consultant on survey design to many public and private sector organizations. From 1970 to 1989 he worked in sampling and survey management at the Survey Research Laboratory, University of Illinois at Chicago.
