SESTAT Survey Design and Methodology

Target Population and
Coverage

Component Surveys

Sample Designs

Data Collection

Editing Guidelines and
Procedures

Missing Data Imputation

Weighting Strategy

Component Surveys

The 1993, 1995, 1997, 1999 and 2001 SESTAT data come from the following surveys: A description of each of these component surveys follows. Some groups of people in the desired target population for SESTAT were not included in the target populations of any of the three component surveys. See Target Population and Coverage above for a description of the difference between the desired target population and the surveyed population.

National Survey of College Graduates (NSCG)

The NSCG primarily covers experienced scientists and engineers (S&E) with a bachelor's or master's degree. Some smaller groups are also included such as those with an S&E Ph.D. earned from a foreign institution or those working in S&E occupations, but with no S&E degree. The National Survey of College Graduates (NSCG) accounts for the largest segment of SESTAT's target population--covering about 80 to 90 percent of the population. The survey, conducted by the U.S. Bureau of the Census, is derived from the 1990 Decennial Census Long Form sample.

The 1993 NSCG was a special baseline survey that included all those who had earned a bachelor's degree or higher prior to 4/1/90 --whether in science or engineering or not. It covered a much larger target population than the usual NSCG--covering over 30 million college graduates, rather than the usual 10 to 12 million S&E's. The sample for this survey was drawn from 1990 Census Long Form respondents -- those residing in the United States on April 1, 1990 or residing abroad as U.S. military personnel.

The 1995 NSCG target population covered the more usual S&E population portion. The sample was selected from 1993 NSCG respondents and 1993 National Survey of Recent College Graduates (NSRCG) respondents (see Sample Designs). Adding the NSRCG group - which will now be referred to as the 1993 NSRCG Panel -- allowed the 1995 NSCG coverage to be more consistent with the 1993 NSCG coverage -- that is those who earned their degree more than two years ago. Specifically, the 1993 NSRCG Panel portion added to the 1995 NSCG were those who earned an S&E degree between April 1, 1990 and June 30 1992. The 1995 NSCG was conducted by the U.S. Census Bureau.

The 1997 NSCG target population followed the same pattern as the 1995 NSCG. That is, the 1997 NSCG sample was selected from the 1995 NSCG (including the 1993 NSCG and the 1993 NSRCG Panel) and the 1995 National Survey of Recent College Graduates (1995 NSRCG Panel) sample. Different portions of the 1997 NSCG sample were conducted by two separate survey organizations. The U.S. Census Bureau administered the original 1993 NSCG portion of the 1997 NSCG sample. Westat, Inc. administered the 1993 NSRCG Panel and the 1995 NSRCG Panel portions. In this year, slightly different versions of the NSCG questionnaire were used by two organizations. The 1993 and 1995 NSRCG Panel sample, being more recent graduates than the original NSCG sample, received one of two NSCG questionnaires, each with several additional questions regarding their plans regarding further education. Two NSCG questionnaires were used by Westat because unlike the portion at the Census Bureau, the NSRCG Panel sample also included nonrespondents to the 1995 NSCG. Both of these questionnaires are referred to as the NSRCG Follow-up (Version A and Version B).

The 1999 NSCG sample was selected from the 1997 NSCG sample (including the 1993 NSCG, and the 1993 and 1995 NSRCG Panels) and the 1997 National Survey of Recent College Graduates sample (1997 NSRCG Panel). Again, different portions of the 1999 NSCG were conducted by two separate survey organizations.  This time, the U.S. Census Bureau administered the 1993 NSCG and the 1993 NSRCG Panel portions.  Westat, Inc. administered the 1995 NSRCG Panel and the 1997 NSRCG Panel portions. As in 1997, slightly different versions of the NSCG questionnaire were used.  The NSRCG Panel samples (more recent graduates) surveyed by Westat received one of two NSCG questionnaires, each with several additional questions regarding their plans regarding further education.  Two questionnaires were used because unlike the portions at the Census Bureau, Westat’s NSRCG Panel samples also included nonrespondents to the 1997 NSRCG. Both of these questionnaires are referred to as the NSRCG Follow-up (Version A and Version B).

The National Survey of College Graduates was not conducted in 2001.

Survey of Doctorate Recipients

The general scope of the Survey of Doctorate Recipients covers individuals who received a doctorate in an S&E field from a U.S. institution. Doctoral level professional degrees such as those awarded in medicine, law, or education are not included.

The 1993 Survey of Doctorate Recipients (SDR) covers the portion of SESTAT's target population that received doctoral degrees in an S&E field from a U.S. educational institution between January 1, 1942 and June 30, 1992. The 1995 SDR includes those who received doctoral degrees in a S&E field from a U.S. educational institution between January 1, 1942 and June 30, 1994. The 1997 SDR includes those who received doctoral degrees in a S&E field from a U.S. educational institution between January 1, 1942 and June 30, 1996. The 1999 SDR includes those who received doctoral degrees in an S&E field from U.S. educational institution between January 1, 1942 and June 30, 1998. The 2001 SDR includes those who received doctoral degrees in an S&E field from U.S. educational institution between January 1, 1942 and June 30, 2000. 

The 1993 and 1995 SDR were conducted by the National Research Council (NRC), which also has been maintaining the Doctorate Records File (DRF), a historical database of U.S. doctorate recipients used in constructing SDR's sampling frame. The 1997 SDR was conducted by National Opinion Research Center (NORC).  The 1999 and 2001 SDR were conducted by the U.S. Census Bureau. NORC has been maintaining the DRF since 1997.

National Survey of Recent College Graduates

In general, the National Survey of Recent College Graduates covers those who received a S&E degree from a U.S. institution in the two academic years prior to the survey reference date. Specifically, the 1993 National Survey of Recent College Graduates (NSRCG) covers the portion of SESTAT's target population that received bachelor's and master's degrees in an S&E field from a U.S. educational institution between April 1, 1990 and June 30, 1992. The Institute for Social Research (ISR) of Temple University selected the samples of educational institutions and recent graduates for the 1993 NSRCG. Westat, Inc., conducted the survey.

The 1995 NSRCG covers those who received bachelor's or master's degrees in an S&E field from a U.S. educational institution between July 1, 1992 and June 30, 1994. Westat, Inc., selected the sample and conducted the survey.

The 1997 NSRCG covers those who received bachelor's or master's degrees in an S&E field from a U.S. educational institution between July 1, 1994 and June 30, 1996. Westat, Inc., selected the sample and conducted the survey.

The 1999 NSRCG covers those who received bachelor's or master's degrees in an S&E field from a U.S. educational institution between July 1, 1996 and June 30, 1998. Westat, Inc., selected the sample and conducted the survey.

The 2001 NSRCG covers those who received bachelor's or master's degrees in an S&E field from a U.S. educational institution between July 1, 1998 and June 30, 2000. Westat, Inc., selected the sample and conducted the survey.

Once individuals have entered the SESTAT system through the NSRCG, a subsample is followed as part of the NSCG. (see section on National Survey of College Graduates).