BPS: Research Methodology Descriptive Summary of 1995-96 Beginning Postsecondary Students: Six Years Later
The Beginning Postsecondary Students Longitudinal Study (BPS: 1996/2001)
Accuracy of Estimates
Data Analysis System
Statistical Procedures
Differences Between Means
Linear Trends
Executive Summary
Full Report (PDF)
Executive Summary (PDF)
The Beginning Postsecondary Students Longitudinal Study (BPS: 1996/2001)

The Beginning Postsecondary Students Longitudinal Study (BPS) is based on a sample of students who were enrolled in postsecondary education for the first time in 1995–96 and participated in the 1995–96 National Postsecondary Student Aid Study (NPSAS:96). NPSAS:96 was a study conducted by the U.S. Department of Education’s National Center for Education Statistics (NCES) consisting of a nationally representative sample of all students enrolled in postsecondary education during the 1995–96 academic year.1 Information for NPSAS:96 was obtained from more than 830 postsecondary institutions for approximately 44,500 undergraduate and 11,200 graduate and first-professional students. The sample of undergraduates represented about 16.7 million students, including about 3 million first-time beginning students, who were enrolled at some time between July 1, 1995 and June 30, 1996.

This BPS study began with a sample of approximately 12,000 students who were identified in NPSAS:96 as having entered postsecondary education for the first time in 1995–96. Unlike other NCES longitudinal surveys (such as the National Education Longitudinal Study of 1988), which follow age-specific cohorts of secondary school students, the BPS sample is more likely to include nontraditional students who have delayed their postsecondary education due to financial need or family responsibilities.

The first follow-up of the BPS cohort (BPS:1996/98) was conducted in 1998, approximately three years after these students first enrolled. Approximately 10,300 of the students who first began in 1995–96 were located and interviewed in the 1998 follow-up for an overall weighted response rate of 79.8 percent. This response rate includes those who were nonrespondents in 1996; among the NPSAS:96 respondents the response rate was 85.9 percent.2 The second follow-up of the BPS cohort (BPS:1996/2001) was conducted in 2001, six years following college entry. All respondents to the first follow-up, as well as a subsample of nonrespondents in 1998, were eligible to be interviewed. Over 9,100 students were located and interviewed. The weighted response rate was 83.6 percent overall, but was somewhat higher among respondents to both the 1996 and the 1998 interviews (87.4 percent).3

Nonresponse among cohort members causes bias in survey estimates when the outcomes of respondents and nonrespondents are shown to be different. A bias analysis was conducted of the 2001 survey results to determine if any variables were significantly biased due to nonresponse.4 Considerable information was known from the 1996 and 1998 surveys for nonrespondents to the 2001 interviews, and nonresponse bias could be estimated using variables with this known in-formation. Weight adjustments were applied to the BPS:1996/2001 sample to reduce any bias found due to unit nonresponse. After the weight adjustments, some variables were found to reflect zero bias, and for the remaining variables the bias did not differ significantly from zero. This analysis was performed on variables found on the frame where the true value is known for both respondents and nonrespondents. For other variables collected in the survey, where data is available only for respondents, it is not known whether the weight adjustments completely eliminate bias.

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