Key Survey Information
Data Collection and Processing
Survey Quality Measures
Data Availability and Comparability
1. Survey Overview (2015 cycle)
- Purpose: The National Survey of College Graduates (NSCG), sponsored by the National Center for Science and Engineering Statistics (NCSES) within the National Science Foundation provides data on the characteristics of the nation's college graduates, with particular focus on those in the science and engineering workforce. It samples individuals who are living in the United States during the survey reference week, have at least a bachelor's degree, and are under the age of 76. By surveying college graduates in all academic disciplines, the NSCG provides data useful in understanding the relationship between college education and career opportunities, as well as the relationship between degree field and occupation.
- Data collection authority: The information collected in the NSCG is solicited under the authority of the National Science Foundation (NSF) Act of 1950, as amended, and the America COMPETES Reauthorization Act of 2010. The U.S. Census Bureau collects the NSCG data under the authority of Title 13, Section 8 of the United States Code. The Office of Management and Budget control number is 3145-0141 and expires on 31 May 2018.
- Major changes to recent survey cycle: The 2015 NSCG continues the implementation of a revised sample design that began in the 2010 cycle. The revised design incorporates sample cases from multiple frames through the use of a rotating panel design. As part of the rotating panel design, every new panel will receive a baseline survey interview and three biennial follow-up interviews before rotating out of the survey.
To continue the transition into the fully implemented rotating panel design, the 2015 NSCG includes 135,000 sample cases drawn from:
- The returning sample from the 2010 NSCG (originally selected from the U.S. Census Bureau's 2009 American Community Survey (ACS)).
- The returning sample from the 2013 NSCG (originally selected from the 2011 ACS and 2010 National Survey of Recent College Graduates (NSRCG)).
- New sample selected from the 2013 ACS.
About 93,000 cases were selected from the set of returning sample members that originated in the 2009 ACS, 2011 ACS, or 2010 NSRCG. These returning sample members were included into the survey in an effort to obtain one of the three biennial follow-up interviews that are part of the rotating panel design. The remaining 42,000 cases were new sample cases selected from the 2013 ACS and will receive a baseline NSCG survey interview.
While most of the returning sample cases are respondents from the 2013 NSCG survey cycle, about 7,000 nonrespondents from the 2013 NSCG survey cycle were included in the 2015 NSCG sample. These 7,000 cases are individuals that responded in the 2010 NSCG survey cycle, but did not respond during the 2013 NSCG survey cycle. These 2013 NSCG nonrespondents were included in the 2015 NSCG sample in an effort to reduce the potential for nonresponse bias in our NSCG survey estimates.
In terms of survey content, the 2015 NSCG includes new questions on the attainment of certifications and licenses.
2. Key Survey Information
- Frequency: Biennial.
- Initial survey year: In 1993, the NSCG replaced the previous biennial collection, the Survey of Natural and Social Scientists and Engineers (SSE), which began in 1972.
- Reference period: The week of February 1, 2015.
- Response unit: Individuals with at least a bachelor's degree.
- Sample or census: Sample.
- Population size: Approximately 58 million individuals.
- Sample size: Approximately 135,000 individuals.
- Key variables:
- Citizenship status
- Certifications and licenses
- Community college attendance (including attendance time period and reasons for attendance)
- Country of birth
- Country of citizenship
- Disability status
- Educational history (for each degree held: field, level, and when received)
- Employment benefits (e.g., health insurance, profit sharing)
- Employment status (e.g., unemployed, employed full time, or employed part time)
- Geographic place of employment
- Immigration status (e.g., year of entry, type of entry visa, reasons for coming to United States)
- Labor force status
- Marital status
- Number of children
- Occupation (current or past job)
- Primary work activity (e.g., teaching, basic research)
- Race and ethnicity
- Satisfaction and importance of various aspects of job
- School enrollment status
- Sector of employment (e.g., academia, industry, government)
- Student financial aid
- Work-related training
3. Survey Design
- Target population: The NSCG target population includes individuals that meet the following criteria:
- Earned a bachelor's degree or higher prior to 1 January 2014
- Are not institutionalized and reside in the United States as of 1 February 2015
- Are less than 76 years of age as of 1 February 2015
- Sample frame: Through the use of a rotating panel design, the NSCG includes samples from the 2013 ACS and the 2013 NSCG. The 2013 NSCG sample cases originated from three different frames: the 2009 ACS, the 2011 ACS, and the 2010 NSRCG.
- Sample design: The NSCG uses a stratified sampling design to select its sample from the eligible sampling frame. Within the sampling strata, the NSCG uses probability proportional to size (PPS) or systematic random sampling techniques to select the NSCG sample. The stratification cells are defined by the following variables:
- Demographic group
- Highest degree type
- Occupation/bachelor's degree field (a composite variable that captures both occupation field and bachelor's degree field).
As was the case in the 2013 NSCG, the 2015 NSCG includes an oversample of young graduates in an effort to improve the precision of estimates for this important population.
4. Data Collection and Processing
- Data collection: The U.S. Census Bureau collected the 2015 NSCG data for NCSES using a multimode data collection approach. Initial data collection used a self-administered web survey. Nonrespondents to the web survey invitation were followed up with a self-administered mail survey. Finally, nonrespondents to the mail survey were followed up using computer-assisted telephone interviewing (CATI). In total, the 2015 NSCG data collection effort lasted approximately six months.
- Data processing: The data collected in the NSCG are subject to both editing and imputation procedures. The NSCG uses both logical imputation and statistical (hot deck) imputation as part of the data processing effort.
- Estimation techniques: Every sample case in the NSCG has a final sample weight that reflects the portion of the overall population the case represents. This final sample weight reflects weighting adjustments that were conducted to account for the following:
- Sample selection
- Trimming procedures to eliminate extreme weights
- Raking procedures to ensure the sampling weights agree with sampling frame estimates
- Overlap procedures to convert weights that reflect the population of each individual frame (2009 ACS, 2011 ACS, 2013 ACS, and 2010 NSRCG) into a final sample weight that reflects the 2015 NSCG target population.
The final sample weights enable data users to derive survey-based estimates of the NSCG target population. The variable name on the NSCG public use data files for the NSCG final sample weight is WTSURVY.
5. Survey Quality Measures
- Sampling error: 2015 NSCG variance estimates were calculated using a combination of the successive difference replication method (for cases that originated in the 2009 ACS, the 2011 ACS, and the 2013 ACS) and the jackknife replication method (for cases that originated in the 2010 NSRCG). Due to the large amount of data collected in the NSCG, it is not always practical to make direct calculations of a variance estimate using replicate weights for every NSCG survey estimate. As a result, generalized variance functions were developed to model the variance estimates for certain characteristics. Generalized variance parameters were then calculated through the use of the generalized variance functions. Generalized variance parameters can be used to calculate standard errors for various types of characteristics.
Please contact the NSCG Project Officer to obtain the NSCG replicate weights or the NSCG generalized variance parameters.
- Coverage error: The concept of coverage in the survey sampling process is the extent to which the total population that could be selected for sample "covers" the survey's target population. Any missed housing units or missed individuals within sample households in the ACS or any missed individual in the NSRCG would create undercoverage in the NSCG. Additional undercoverage errors may exist because of self-reporting errors in the NSCG sampling frame that led to incorrect classification of individuals as not having bachelor's degrees or above when in fact they held such a degree.
- Nonresponse error: The weighted response rate for the 2015 NSCG was 70%. Results from the research and analysis of NSCG nonresponse trends have been used in the development of the nonresponse weighting adjustments to minimize the potential for nonresponse bias in the NSCG estimates.
The NSCG item nonresponse rate for key items (employment status, type of employment, occupation, and primary work activity) ranged from 0.0% to 0.6%. Other variables, especially those involving sensitive information, had higher nonresponse rates. For example, salary and earned income had item nonresponse rates of approximately 10% to 12%. A hot deck imputation method was used to compensate for the item nonresponse.
- Measurement error: The NSCG is a survey of individuals and thus subject to reporting errors from differences in interpretation of questions. It is also true for any multimodal survey (web, mail, CATI) that some measurement errors will differ by modality. To reduce measurement errors, the NSCG questionnaire items were pretested in focus groups and cognitive interviews.
Please contact the NSCG Project Officer to obtain further information on NSCG survey evaluation research.
6. Data Availability and Comparability
- Data availability Data from 1993 to present are available through NCSES's NSCG website at https://www.nsf.gov/statistics/srvygrads/. Contact the NSCG Project Officer for more information on historical data.
- Data comparability: Year-to-year comparisons can be made among the 1993, 2003, 2010, 2013, and 2015 NSCG survey years because many of the core questions remained the same across the survey cycles. Small but notable differences exist across some survey years, however, such as the collection of occupation and education data being based on the different versions of the Standard Occupational Classification (SOC) and Classification of Instructional Programs (CIP). Also, due to the reference month differences in some survey cycles, seasonal differences may occur when making comparisons across years and decades. As a result, use caution when interpreting across-year and across-decade comparisons.
There is overlap in the cases included in the 2010 NSCG, 2013 NSCG, and 2015 NSCG, which allows for the ability to conduct longitudinal analysis of this subset of the NSCG sample. This sample overlap consists of cases that originated in the 2009 ACS or the 2011 ACS. To link cases on the NSCG public use data files across survey years, use the REFID unique identification variable. To aid in this longitudinal analysis, single-frame weights are available for each survey year that allow for the evaluation of estimates from each frame independently. Please contact the NSCG Project Officer to obtain the single-frame weights for the 2010, 2013, and 2015 NSCG.
7. Data Products
- Publications: Data from the NSCG are published in NCSES InfoBriefs and data tables, available at https://www.nsf.gov/statistics/srvygrads/.
Information from this survey is also included in Science and Engineering Indicators and Women, Minorities, and Persons with Disabilities in Science and Engineering.
- Electronic access: The NSCG public use data are available in the SESTAT data tool and in public use downloadable files available through the NCSES data download page. The NSCG restricted use data are only available through the U.S. Census Bureau's Federal Statistical Research Data Centers.
8. Contact Information
For additional information about this survey, contact the Project Officer listed below.
Human Resources Statistics Program
National Center for Science and Engineering Statistics
National Science Foundation
4201 Wilson Boulevard, Suite 965
Arlington, VA 22230