The data in this report come from surveys conducted by the National Center for Science and Engineering Statistics (NCSES), National Science Foundation; National Center for Education Statistics (NCES), Department of Education; Census Bureau, Department of Commerce; and Bureau of Labor Statistics, Department of Labor. In addition, administrative data come from the Office of Personal Management. The technical notes for this report provide detailed information on specific data sources.

The degree award data from NCES cover degrees in the following science and engineering fields: astronomy, chemistry, physics, atmospheric sciences, earth sciences, ocean sciences, mathematics and statistics, computer sciences, agricultural sciences, biological sciences, psychology, social sciences, and engineering. To present data in a condensed form for this report, in some cases fields were aggregated in figures and in the text. Data on degree awards include associate’s, bachelor's, master's, and doctoral degrees and do not include professional degrees, such as the MD or JD. The exception is data from the Early Career Doctorates Survey which does include holders of MD degrees.

Data on population projections are from the Census Bureau, 2017 National Population Projections Tables (https://www.census.gov/data/tables/2017/demo/popproj/2017-summary-tables.html). U.S. labor force statistics are from the Bureau of Labor Statistics Current Population Survey, monthly microdata files. Information on the Current Population Survey is at https://www.bls.gov/cps/, and the monthly microdata files are at https://www.census.gov/data/datasets/time-series/demo/cps/cps-basic.html. Statistics on part-time workers and annual unemployment rate are from the Bureau of Labor Statistics, Current Population Survey, 2019, table 8, cpsaat08 (https://www.bls.gov/cps/cpsaat08.htm).

Racial and ethnic categories reported are those mandated by the Office of Management and Budget (OMB) effective 1 January 2003. OMB specified the following categories of racial and ethnic groups: Black or African American; American Indian or Alaska Native; Asian; Native Hawaiian or Other Pacific Islander; White; Hispanic or Latino regardless of race; and more than one race. In earlier volumes, racial and ethnic groups were identified as White, Black, Hispanic, Asian or Pacific Islander, and American Indian or Alaska Native (for more details, see the technical notes for this report). Because of insufficient sample size in some surveys, not all racial or ethnic groups are reported in all tables or figures.

Information on race and ethnicity is presented only for U.S. citizens and permanent residents in NCSES’s Survey of Graduate Students and Postdoctorates in Science and Engineering enrollment data and in NCES’s enrollment and degree award data. However, the proportions of students by race and ethnicity are calculated based on the total number of students enrolled or earning degrees, including those who have temporary visas in themes 1 (Enrollment) and 2 (Field of degree: Women). Elsewhere the total number of degrees received is based on U.S. citizens and permanent residents.