To improve the predictive validity of Structured Interview assessments of Type A behavior by comparing interviewer techniques in the Multiple Risk Factor Intervention Trial (MRFIT) and the Western Collaborative Group Study (WCGS). To assess whether there were interviewer differences in the predictiveness of Type A behavior and its components for coronary heart disease incidence in MRFIT and WCGS and if so, to assess whether the interviewer differences in disease predictiveness were related to interviewer stylistics.