This report presents data on the demographic and employment characteristics of doctoral scientists and engineers in the United States. This 1991 survey is different from prior surveys in this series in that it represents an interest to accommodate an age-based cohort policy in retirement patterns and to make the sample frame compatible with other National Science Foundation surveys of science and engineering personnel. In addition to general notes, this report includes detailed statistical tables, technical notes, and the survey instrument. The statistical tables unit includes employment and salary detail tables. The technical notes section contains information on survey methodology, coverage, concepts, definitions, and sampling errors. (ZWH)