An approach to developing job task inventory questionnaires by interviewing supervisors or job incumbents is described. An initial interview provides the bulk of the information from which task statements will be extracted. A verification interview is conducted with a different interviewee to check and modify information obtained in the initial interview and to uncover aspects of the work that may have been overlooked previously. A follow-up interview is conducted with the previous interviewees to review and modify a draft of the job inventory questionnaire. Applications of job task inventory questionnaires in studies of engineering, sales, and clerical jobs are described, and summaries of study results are presented. (Author)