The first cycle of NSOPF was conducted in 1987-1988 with a sample of 480 institutions (including 2-year, 4-year, doctorate-granting, and other colleges and universities), over 3,000 department chairpersons, and over 11,000 instructional faculty. The response rates for the three surveys were 88, 80, and 76 percent, respectively.

The 1992-93 study (NSOPF:93) was limited to surveys of institutions and faculty, but with a substantially expanded sample of 974 public and private not-for-profit degree-granting postsecondary institutions and 31,354 faculty and instructional staff. The response rates for the two surveys were 94 and 84 percent, respectively.

The 1998-99 National Study of Postsecondary Faculty (NSOPF:99) included 960 degree-granting postsecondary institutions and an initial sample of faculty and instructional staff from those institutions. Approximately, 28,600 faculty and instructional staff were sent a questionnaire. Subsequently, a subsample of 19,813 faculty and instructional staff was drawn for additional survey followup. Approximately 18,000 faculty and instructional staff questionnaires were completed for a weighted response rate of 83 percent. The response rate for the institution survey was 93 percent.

The 200304 National Study of Postsecondary Faculty (NSOPF:04) included a sample of 1,080 public and private not-for-profit degree granting postsecondary institutions and a sample of 35,000 faculty and instructional staff. The weighted response rates for the two surveys were 86 and 76 percent, respectively.

All four cycles of NSOPF gathered information regarding the backgrounds, responsibilities, workloads, salaries, benefits, attitudes, and future plans of both full- and part-time faculty. In addition, information was gathered from institutional and department-level respondents (department-level data collected in 1988 only) on such issues as faculty composition, turnover, recruitment, retention, and tenure policies.

The institution universe for NSOPF has been defined by the following criteria: Title IV participating, degree-granting institutions; public and private not-for-profit institutions; institutions that confer associate's, bachelor's, or advanced degrees; and institutions that are located in the United States.

A two-stage stratified, clustered probability design was used to select the various NSOPF samples. For instance, the first-stage sampling frame for NSOPF:04 consisted of the 3,381 postsecondary institutions in IPEDS that were public or private not-for-profit Title IV participating institutions and provided formal degree programs of at least two years' duration. While the IPEDS universe includes private institutions that are both for-profit and not-for-profit, the institutional universe for NSOPF excludes the private for-profit institutions.

The 3,381 institutions in the NSOPF:04 universe were stratified based on the highest degrees they offered and the amount of federal research dollars they received. These strata distinguished public and private institutions, as well as several types of institutions based on the Carnegie Foundation's classification system.

Unlike NSOPF:88, which was limited to faculty whose assignment included instruction, the faculty universes for NSOPF:93, NSOPF:99, and NSOPF:04 were expanded to include all those who were designated as faculty, whether or not their responsibilities included instruction, and other (non-faculty) personnel with instructional responsibilities. Under this definition, researchers and administrators and other institutional staff who held faculty positions, but who did not teach, were included in the samples. Instructional staff without faculty status also were included. Teaching assistants were not included in any cycle of NSOPF.