Technical Notes
The data in this report come from many sources, including surveys conducted by the National Science Foundation (NSF), other federal agencies, and nonfederal organizations. Many methods of data collection are represented. Therefore, users should take great care when comparing data from different sources. These data often will not be strictly comparable because of differences in definitions, survey procedures, and phrasing of questions, among other things. Efforts have been made to maintain consistency throughout these tables, but in some, it has been necessary to use distinct terminology that does not match that used in other tables.
Reporting Categories
Racial/Ethnic Information
The collection and reporting of race/ethnicity data pose several problems. First, both the naming of population subgroups and their definitions have changed over time. Second, many of the groups of particular interest are quite small, so it is difficult to measure them accurately without surveys of the entire population of interest. In some instances, sample surveys may not have had sufficient sample to permit the calculation of reliable racial/ethnic population estimates for all groups; consequently, data are not shown for some groups. The U.S. Bureau of the Census's Current Population Survey, for example, cannot provide data on American Indians. Third, data on race/ethnicity are often based on self-identification. These data are less reliable for some racial/ethnic groups than for others. Data collected at two points in time indicate that self-identification of American Indians is much less reliable than self-identification of other racial/ethnic groups (U.S. Bureau of Labor Statistics 1995). Fourth, it is easy to overlook or minimize heterogeneity within subgroups when only a single statistic is reported for a total racial/ethnic group.
OMB Categories and Guidelines
In October 1997 the U.S. Office of Management and Budget (OMB) announced new government-wide standards for the collection of data on race and ethnicity (http://www.whitehouse.gov/omb/fedreg_1997standards/) effective 1 January 2003. OMB specified the following categories and definitions of racial/ethnic groups:
- Black or African American: A person having origins in any of the black racial groups of Africa
- American Indian or Alaska Native: A person having origins in any of the original peoples of North and South America (including Central America) and who maintains tribal affiliation or community attachment
- Asian: A person having origins in any of the original peoples of the Far East, Southeast Asia, or the Indian subcontinent; for example, Cambodia, China, India, Japan, Korea, Malaysia, Pakistan, the Philippine Islands, Samoa, Thailand, and Vietnam
- Native Hawaiian or Other Pacific Islander: A person having origins in any of the original peoples of Hawaii, Guam, or other Pacific islands
- White: A person having origins in any of the original peoples of Europe, the Middle East, or North Africa
- Hispanic or Latino: A person of Cuban, Mexican, Puerto Rican, South or Central American, or other Spanish culture or origin, regardless of race
- More than one race reported: A person reporting two or more of the racial/ethnic categories listed above
Previously, racial/ethnic groups were identified as white; black; Hispanic; Asian or Pacific Islander; and American Indian or Alaskan Native. Because data on undergraduate enrollment and degree data were still collected under the old standards through 2008, the racial/ethnic groups described in those tables are designated by the old categories. The National Center for Education Statistics (NCES) changed race/ethnicity reporting in fall 2008 for degrees and enrollments data, but reporting in the new categories is optional through 2010. Reporting in the new race/ethnicity categories will be mandatory for the 2011–12 data collection (i.e., 2011 data). Similarly, because few schools collected racial/ethnic data according to the new standards and few reported graduate enrollment according to the new standards, the racial/ethnic groups described in the graduate enrollment tables are designated by the old categories. NCES and graduate enrollment data by race/ethnicity in this report refer to U.S. citizens and permanent residents only.
Minority-Serving Institutions
High-Hispanic enrollment institutions are institutions of higher education whose full time equivalent (FTE) enrollment of undergraduate students is at least 25% Hispanic, according to enrollment data that institutions reported to the fall 2006 Integrated Postsecondary Education Data System (IPEDS) survey. (This survey is conducted by the National Center for Education Statistics [NCES].) NCES determined FTE enrollment by calculating that approximately three part-time students are equivalent to one full-time student. The FTE numbers should be considered an approximation only because IPEDS does not collect part-time credit hour information. The list includes only non-profit public and private institutions of higher education.
Historically black colleges and universities (HBCUs) are those colleges and universities listed by the White House Initiative on Historically Black Colleges and Universities. The Higher Education Act of 1965, as amended, defines an HBCU as "any historically black college or university that was established prior to 1964, whose principal mission was, and is, the education of black Americans, and that is accredited by a nationally recognized accrediting agency or association determined by the Secretary [of Education] to be a reliable authority as to the quality of training offered or is, according to such an agency or association, making reasonable progress toward accreditation."
Tribal colleges are those colleges that are members of the American Indian Higher Education Consortium and that are included as tribal colleges in the Carnegie Classification of Institutions of Higher Education's 2005 basic classification scheme. See http://www.aihec.org/colleges/TCUroster.cfm and http://classifications.carnegiefoundation.org/lookup_listings/standard.php.
Information About People with Disabilities
Data on people with disabilities who study or work in science and engineering (S&E) are seriously limited for several reasons. First, the operational definitions of disability vary, can include a wide range of physical and mental conditions, and may not be comparable. The Americans with Disabilities Act of 1990 (ADA) encouraged progress toward standard definitions. Under ADA, an individual is considered to have a disability if he or she has a physical or mental impairment that substantially limits one or more of his or her major life activities, has a record of such impairment, or is regarded as having such an impairment. ADA also contains definitions of specific disabilities.
Second, data on disabilities frequently are not included in comprehensive institutional records (e.g., in registrars' records in institutions of higher education). If included at all, such information may be kept only in confidential files at an office responsible for providing special services to students. Institutions of higher education are unlikely to have information regarding students with disabilities who have not requested special services related to their disabilities from the institutions. In elementary/secondary school programs receiving funds to provide special education, however, statistics on all students identified as having special needs are centrally available.
Third, information about people with disabilities that is gathered from surveys is often obtained from self-reported responses. Typically, respondents are asked whether they have a disability and to specify what kind of disability it is. Resulting data therefore reflect individual perceptions rather than objective measures.
The attempt to provide estimates of the proportion of the undergraduate student population with disabilities is an example of how these factors coalesce. Self-reported data on the undergraduate student population, collected through a survey to ascertain patterns of student financial aid, suggest that about 10% of this population has some disability. Estimates from population surveys of higher education institutions, in contrast, place the estimate much lower, between 1% and 5%. Whether this discrepancy is the result of self-perception, incomplete reporting, disabilities that are not evident, or differing definitions is difficult to ascertain.
In the final analysis, although considerable information is available about individuals with disabilities in the educational system and in the S&E workforce, it is often impossible to compare statistics from different sources.
Several sources of data on people with disabilities are cited here. They include the National Postsecondary Student Aid Study (NPSAS) conducted by the Department of Education's National Center for Education Statistics (NCES); the NSF Survey of Earned Doctorates (SED); and the NSF Scientists and Engineers Statistical Data System (SESTAT). These sources are described in more detail later in this appendix; the following is a brief description of how each source treats the issue of disability.
- NPSAS (2008) asked students whether they had any long-lasting condition (6 months or more) "such as blindness, deafness, or a severe vision or hearing impairment" or "that substantially limits one or more basic physical activities, such as walking, climbing stairs, reaching, lifting, or carrying" or "any other physical, mental, emotional, or learning condition that has lasted 6 months or more."
- SED asks if the respondent has a disability then asks the respondent to mark which of the following categories describe the disability(ies): blind/visually impaired, deaf/hard of hearing, physical/orthopedic disability, learning/cognitive disability, vocal/speech disability, other disability.
- The SESTAT surveys ask the degree of difficulty—none, slight, moderate, severe, or unable to do—an individual has in seeing (with glasses or contact lenses), hearing (with hearing aid), walking without assistance, or lifting 10 pounds or more. Those respondents who answered "moderate," "severe," or "unable to do" for any activity are classified as disabled.
Primary Data Sources
Data from several sources are presented here. This section provides summary descriptions of major sources and information about the location of more detailed survey descriptions.
Primary NSF Sources
The following sources from NSF's Division of Science Resources Statistics (SRS) were used for data tables in this publication. Published data tables from these surveys can be accessed on the SRS Website. In addition, researchers may access data directly from the Scientists and Engineers Statistical Data System (SESTAT) or the WebCASPAR database system, which also can be accessed from the SRS Website.
Survey of Earned Doctorates
The Survey of Earned Doctorates (SED) has been conducted annually since 1957 for NSF, the U.S. Department of Education, the National Endowment for the Humanities, the National Institutes of Health, the National Aeronautics and Space Administration, and the U.S. Department of Agriculture. This survey is of all recipients of research doctoral degrees from U.S. institutions. SED data are restricted to research doctorates, such as the doctor of philosophy (PhD) or doctor of science (DSc); it excludes the recipients of professional degrees, such as the juris doctor (JD) or doctor of medicine (MD).
Data for the SED are collected directly from individual doctorate recipients contacted through graduate deans at all U.S. universities awarding research doctorates. The recipients are asked to provide information about the fields and specialties of their degrees as well as their personal educational histories, selected demographic data, and information about their postgraduate work and study plans. Over time, more than 90% of the annual cohort of doctorate recipients has responded to the questionnaire.
Partial data from public sources, such as field of study, are added to the file for nonrespondents. No imputations for nonresponse are made, however, if data are not available elsewhere (e.g., race/ethnicity information). The data for a given year include all doctorates awarded in the 12-month period ending on 30 June of that year. Information about the SED can be found at http://www.nsf.gov/statistics/srvydoctorates/.
Survey of Graduate Students and Postdoctorates in Science and Engineering
The data collected in the Survey of Graduate Students and Postdoctorates in Science and Engineering (GSS) represent national estimates of graduate enrollment and postdoctoral employment (postdocs) at the beginning of the academic year in all academic institutions in the United States that offer doctoral or master's degree programs in any S&E or health field. Included are data for all branch campuses; affiliated research centers; and separately organized components, such as medical or dental schools, schools of nursing, and schools of public health. The survey population consists of approximately 600 graduate institutions. Data are collected separately for each eligible organizational unit (academic department or program, research center, or health facility).
Approximately 97%–98% of institutions and units respond to the survey. Missing data for nonrespondent units are imputed using prior years' data, where available, or data from peer institutions in cases where data had not been reported the previous 5 years.
The tables in this report present only 2008 data. In 2007 communication, family and consumer science/human science, and multidisciplinary/interdisciplinary studies were added to the survey as science fields. Architecture, which had previously been reported under civil engineering, was reclassified as a separate engineering field. Neuroscience, which had previously been reported under health, was reclassified as a science field. Survey respondents were also asked to review and update each organizational unit's assigned field of study. As a result, survey respondents reported students and postdocs in some units in different fields in 2007 and 2008 than they had in previous years. Due to these methodological changes in 2007, the data collected in 2007 and 2008 are not strictly comparable to those collected before 2007.
The GSS collects data by race/ethnicity only for U.S. citizens and permanent residents. In 1999, the survey presented respondents with new race/ethnicity categories:
- The "Asian/Pacific Islander" category used in previous years' surveys became two categories: "Asian" and "Native Hawaiian/Pacific Islander."
- The categories "more than one race Hispanic/Latino" and "more than one race non-Hispanic/Latino" were added.
- The "other" category included in previous years' surveys was removed.
These changes are not reflected in the tables in this report. Currently, fewer than 8% of the units report data in any of the new categories. For the tables in this report, as in other publications using these data, the data reported in the new categories are combined into previous survey categories. The data are combined for the tables as follows: the "Asian" category and the "Native Hawaiian/Pacific Islander" category form the "Asian/Pacific Islander" category; the "one race only Hispanic/Latino" category and the "more than one race Hispanic/Latino" category form the "Hispanic" category; and the "more than one race non-Hispanic" category and the "unknown" category form the "other or unknown" category. Information about GSS can be found at http://www.nsf.gov/statistics/srvygradpostdoc/.
SESTAT Data System
The SESTAT data system integrates data from three SRS surveys—the Survey of Doctorate Recipients (SDR), the National Survey of College Graduates, and the National Survey of Recent College Graduates (NSRCG). The integration of the SESTAT surveys requires complementary sample populations and reference periods; matching survey questions, procedures, and field definitions; and weighting adjustments for any overlapping populations.
The surveys provide data on educational background, occupation, employment, and demographic characteristics. These surveys are of individuals and currently have a combined sample size of about 105,000, representing a population of about 22.6 million scientists and engineers, including people trained in S&E or S&E-related fields or working in S&E or S&E-related occupations. Each of the three surveys that make up the SESTAT data system collects new data every 2 years.
SESTAT defines scientists and engineers as residents of the United States with a baccalaureate degree or higher who, as of the study's reference period, were not institutionalized, were age 75 or younger, and were either educated as or working as a scientist or engineer. A baccalaureate or higher degree is a bachelor's, master's, doctoral, or professional degree. To meet the scientist or engineer definition, the U.S. resident had to (1) have at least one baccalaureate or higher degree in an S&E or S&E-related field or (2) as of 1 October 2003, have a baccalaureate or higher degree in a non-S&E field but work in an S&E or S&E-related occupation. Some elements of SESTAT's desired target population were not included within the target populations of any of the three SESTAT component surveys. Science and engineering or S&E-related personnel missing from the survey frames in 2006 are primarily foreign-educated scientists and engineers who came to the United States after 1 April 2000 and people with non-S&E degrees who took S&E or S&E-related jobs after 1 October 2003.
SESTAT classifies the following broad categories as S&E occupations: computer and mathematical scientists, life and related scientists, physical and related scientists, social and related scientists, and engineers. Postsecondary teachers are included within each of these groups. The following are considered S&E-related occupations: health and related occupations; S&E managers; S&E precollege teachers; S&E technicians and technologists, including computer programmers; and other S&E-related occupations, such as architects and actuaries. Non-S&E occupations include non-S&E managers; non-S&E teachers; non-S&E technicians/technologists; social services and related occupations; sales and marketing occupations; art, humanities, and related occupations; and other non-S&E occupations—for example, clerical and administrative support personnel; farmers, foresters, and fishermen; lawyers and judges; librarians, archivists and curators; food service personnel; construction tradespeople; mechanics and repairers; those involved in precision/production occupations; operators (for example, machine set-up, machine operators and tenders, fabricators, assemblers) and related occupations; transportation/material moving occupations; and protective and other service occupations. Information on SESTAT can be found at http://www.nsf.gov/statistics/sestat/.
SESTAT data presented in this report are for 2006. Previously published data on doctorate holders for 2003 and 2006 from the SDR component of SESTAT erroneously included some individuals reporting two or more races in other individual racial/ethnic categories. Those data have now been corrected and tables in this report were made using the corrected SESTAT data files. Corrected data are noted "r" in the data tables. For the most accurate data, use only these most recent tables.
Data from two of the SESTAT surveys, the SDR and the NSRCG, are also presented separately in this report. The sampling frame for the 2008 SDR included individuals living in the United states on 1 October 2008 who had earned a research doctoral degree from a U.S. college or university in a science, engineering, or health field through 30 June 2007; were U.S. citizens or, if non-U.S. citizens, had indicated plans to remain in the United States after receiving their doctoral degrees; and were younger than age 76. In 2008 the SDR sample size was approximately 40,000. The weighted response rate was 81%. Because the final 2008 SDR file had not been released when the tables in this report were made, preliminary 2008 SDR data were used. The sampling frame for the 2008 NSRCG included individuals living in the United States on 1 October 2008 who had earned a bachelor's or master's degree from a U.S. college or university in a science, engineering, or health field between 1 July 2005 and 30 June 2007 and were younger than age 76. In 2008 the NSRCG sample size was 18,000. The overall weighted response rate was 70%.
Primary Non-NSF Sources
The following non-NSF sources were used for data tables in this report.
The Integrated Postsecondary Education Data System Survey: Fall Enrollment, Completions, and Institutional Characteristics
National Center for Education Statistics, U.S. Department of Education (http://nces.ed.gov/ipeds)
The Integrated Postsecondary Education Data System (IPEDS) Survey began in 1986 as a supplement to and replacement for the Higher Education General Information Survey (HEGIS), which began in 1966. HEGIS annually surveyed institutions listed in the current NCES Education Directory of Colleges and Universities; IPEDS surveys all postsecondary institutions, including universities and colleges and the institutions that offer technical and vocational education. The completion of all IPEDS surveys is mandatory for all institutions that participate in or are applicants for participation in any federal financial assistance program authorized by Title IV of the Higher Education Act of 1965, as amended. IPEDS comprises several integrated component surveys that obtain information about types of institutions where postsecondary education is available, student participants, fall enrollments, programs offered and completed, graduation rates, and the human and financial resources involved in the delivery of postsecondary education. Descriptions of these surveys follow.
IPEDS Fall Enrollment Survey. This survey replaces and extends the previous HEGIS surveys of enrollment in institutions of higher education.
IPEDS Completions Survey. This survey replaces and extends the HEGIS Degrees and Other Formal Awards Conferred Survey. It is administered to all institutions offering degrees at the bachelor's degree level and above, 2-year institutions, and less-than-2-year institutions.
NCES changed degree-level categories in the IPEDS Completions Survey in fall 2008, but reporting in the categories is optional for 2008 and 2009 data. Reporting in the new degree-level categories will be mandatory for the 2010–11 (2010 data) IPEDS collection. Before 2008 the post-baccalaureate degree categories were "master's," "first professional," and "doctor's." With the 2008 changes, the category "first professional" degree is no longer used. Programs and awards in that category (e.g., medicine, law, pharmacy, theology) are now reclassified as either master's degrees or as one of three types of doctor's degrees: doctor's—research/scholarship, doctor's—professional practice, or doctor's—other. Numbers reported here for 2008 doctoral degrees combine doctor's degrees reported by institutions using the pre-2008 reporting categories and doctor's—research/scholarship degrees reported by institutions using the 2008 reporting categories.
IPEDS Institutional Characteristics Survey. This survey provides the basis for the list of institutions reported in the Education Directory of Colleges and Universities. The list includes institutions that meet specific accreditation criteria and offer at least a 1-year program of college-level studies leading to a degree. Each fall, institutions listed in the previous year's directory are asked to update information about their school's characteristics.
The National Postsecondary Student Aid Study
National Center for Education Statistics, U.S. Department of Education (http://nces.ed.gov/npsas)
The National Postsecondary Student Aid Study (NPSAS) was established by NCES to collect information about financial aid allocated to students enrolled in U.S. postsecondary institutions. NPSAS was first administered in the fall of the 1986–87 academic year. NCES conducted subsequent cycles of NPSAS during the 1989–90, 1992–93, 1995–96, 1999–2000, 2003–04, and 2007–08 academic years.
The 2007–08 survey gathered information from about 127,700 undergraduate and graduate students selected from registrars' lists of enrollees at more than 1,900 postsecondary institutions. Student information, such as field of study, educational level, and attendance status (part time or full time), was obtained from registrars' records. Types and amounts of financial aid and family financial characteristics were abstracted from school financial aid records. Data pertaining to family circumstances, background demographic data, educational and work experiences, and expectations were collected from students using self-administered or interviewer-administered, Web-based interviews. The weighted response rate was 96%.
Current Population Survey
Bureau of Labor Statistics, U.S. Department of Labor (http://www.bls.gov/cps/)
The Current Population Survey (CPS) is a monthly household survey conducted by the U.S. Census Bureau for the Bureau of Labor Statistics. It provides data on employment and unemployment by age, sex, race, and a variety of other characteristics. CPS surveys approximately 60,000 households through personal and telephone interviews. Basic labor-force data are gathered monthly; data on special topics are gathered in periodic supplements. Consecutive monthly estimates are often averaged to produce quarterly or annual average estimates. Monthly response rates are generally above 90%.
Survey of Engineering and Technology Enrollments and Survey of Engineering and Technology Degrees
Engineering Workforce Commission, American Association of Engineering Societies (http://www.ewc-online.org/)
The Engineering Workforce Commission (EWC) annually conducts surveys of engineering and engineering technologies enrollments and degrees conferred in more than 600 institutions, including all of those with curricula approved by the Accreditation Board for Engineering and Technology (ABET). EWC counts the number of students studying for engineering degrees at all ABET-accredited engineering schools throughout the United States and also some schools that are not ABET-accredited for a variety of reasons unique to each school. Some schools are in the process of obtaining ABET accreditation; others have simply asked to be included in the survey. The fall 2008 enrollments survey obtained responses from about 85% of the schools. Data for nonrespondent schools were imputed.
Sampling and Nonsampling Errors
The data from all of the sources used for this report are subject to error. Survey accuracy is determined by the joint effects of sampling and nonsampling errors. Sampling errors arise because estimates based on a sample differ from figures that would have been obtained if a complete population had been surveyed. The sample used for any particular survey is only one of a large number of possible samples of the same size and design that could have been selected. Even if all other aspects of the survey remained fixed, such as the questionnaire and instructions, the estimates from each sample would differ from other samples. This difference, termed sampling error, occurs by chance, and its variability is measured by the standard error associated with a particular estimate.
The standard error of a sample survey estimate measures the precision with which an estimate from one sample approximates the true population value, and it can be used to construct a confidence interval for a survey parameter to assess the accuracy of the estimate. See http://www.nsf.gov/statistics/sestat/calcerror.cfm for information about calculation of standard errors for data from SESTAT, http://www.bls.gov/cps/documentation.htm for Current Population Survey design and methodology, and http://nces.ed.gov/pubs2009/2009166.pdf for information on standard errors for NPSAS data.
Nonsampling errors can arise from design, reporting, and processing errors as well as from errors due to faulty responses or nonresponses. Nonsampling errors include respondent-based events, such as some respondents interpreting questions differently from other respondents; respondents making estimates rather than giving actual data; and respondents being unable or unwilling to provide complete, correct information. Errors can also arise during the processing of responses, such as during recording and keying. Nonsampling errors are difficult to measure and estimates of nonsampling errors are not available for data in this report.
Reference
U.S. Bureau of Labor Statistics. 1995. A Test of Methods for Collecting Racial and Ethnic Information. Washington, DC: U.S. Department of Labor. Available at http://stats.bls.gov/news.release/ethnic.toc.htm.
