PEDAR: Research Methodology Debt Burden - A Comparison of 1992–93 and 1999–2000 Bachelor’s Degree Recipients a Year After Graduating
Baccalaureate and Beyond Longitudinal Study
Overall Response Rates
Weight Variables
Accuracy of Estimates
Item Response Rates and Bias Analysis
Data Analysis System
Statistical Procedures
Differences Between Means
Executive Summary
Full Report (PDF)
Executive Summary (PDF)
 Accuracy of Estimates

The statistics in this report are estimates derived from a sample. Two broad categories of error occur in such estimates: sampling and nonsampling errors. Sampling errors occur because observations are made on only samples of students, not entire populations. Nonsampling errors occur not only in sample surveys but also in complete censuses of entire populations. Nonsampling errors can be attributed to a number of sources: inability to obtain complete information about all students in all institutions in the sample (some students or institutions refused to participate, or students participated but answered only certain items); ambiguous definitions; differences in interpreting questions; inability or unwillingness to give correct information; mistakes in recording or coding data; and other errors of collecting, processing, sampling, and imputing missing data. Readers interested in efforts to minimize nonsampling errors for estimates used in this report should consult the methodology reports referenced earlier in this appendix.

next section