Assessing comprehension in a survey of public reactions to complex issues

This paper reports results of research to develop household interview procedures for obtaining reasonably informed public judgements about ethical issues in biomedical research. We describe (1) an interviewing strategy designed to enhance comprehension among survey respondents, and (2) a composite comprehension index based on three types of information from the interview. Using data from a cross-section sample, we identify subgroups that differ significantly with respect to scores on the comprehension index, and we then describe the observed levels of comprehension in terms of the operations defining the index. The results demonstrate both the feasibility and limits of obtaining informed rather than naive judgements about complex issues from lay respondents.