nsf.gov - SRS US Doctorates in the 20th Century - US National Science Foundation (NSF)

This section provides definitions of key terms used in this report and explanatory information on the treatment of certain variables. For convenience, the Doctorate Records File is referred to as the DRF throughout the section, and the Survey of Earned Doctorates is referred to as the SED.

The degree information in the DRF reflects the first degree earned by the individual at each level, as applicable: first baccalaureate, first master's degree, first professional doctorate, and first research doctorate. Survey forms for any subsequent research doctorates are retained but are not entered into the DRF.

Doctorate recipients report their immediate postgraduation plans for employment or additional study. This report focuses on Ph.D.s who reported definite plans at the time they completed the SED, which is usually shortly before graduation. Ph.D.s with definite plans include those who reported they had signed a contract or had otherwise made a commitment for a new position as well as those who reported they were returning to or continuing in a position held before graduation. Most analyses in this report are further restricted to commitments in the United States.

In this report the standard practice is to use the median to report the age of doctorate recipients. Half of the Ph.D.s are older than the median age, and half are younger. The year of birth is required for this computation. The month of birth is used when available.

Carnegie Classification. A system of classification of postsecondary institutions established by the Carnegie Foundation for the Advancement of Teaching.

Carnegie classifications are based on highest degree conferred, fields in which degrees are conferred, number of programs, enrollment, research support, and selectivity of admissions criteria. The classifications are updated periodically by the Carnegie Foundation to reflect changes in the characteristics of institutions. This report used the 1994 Carnegie update to describe the institutions that awarded doctorates in the 1990s. The Carnegie categories are as follows: Research I and II, Doctoral I and II, Master's I and II, Baccalaureate I and II, Associate of Arts (not applicable to this report), Religion and Theology, Medical, Other Health, Engineering, Business, Fine Arts, Law, Teachers College, Other Specialized (e.g., maritime academy, military institute), and Tribal College (not applicable to this report). A majority of the doctorate-granting institutions are classified as Research (126) or Doctoral (109) institutions, and they account for the vast majority of doctorates awarded in the United States. In 1990–99, Research I institutions conferred 68.3 percent of all doctorates; Research II institutions, 11.5 percent; Doctoral I institutions, 10.6 percent; and Doctoral II institutions, 4.4 percent. Although a substantial number of doctorate-granting institutions fall into the "other" Carnegie categories, together they awarded 5.3 percent of all doctorates in the 1990s; these institutions were aggregated and presented as the "other" Carnegie group in this report.

Citizenship status. Most citizenship data are presented as reported by the doctorate recipients or as provided by the institutions that granted the doctorates. The following logical assumptions were made in certain situations:

Debt status and level. Included is debt that is directly related to the doctorate recipient's undergraduate and graduate education and is still owed at graduation. Education-related expenses include tuition and fees, living expenses and supplies, and transportation to and from school.

Doctorate-granting institution. Any postsecondary institution in the United States that awards research doctorates (as defined below) and is accredited by an agency recognized by the Secretary of the U.S. Department of Education is a doctorate-granting institution.

Currently there are about 400 doctorate-granting institutions. The number can fluctuate from year to year for various reasons: (1) additional institutions become doctorate-granting, (2) some institutions with small programs do not award doctorates every year, and (3) a few institutions eliminate their doctoral programs altogether.

The institutions that awarded doctorates before 1920 (the first year of data in the DRF) were determined from annual reports of the U.S. Office of Education (USEO 1869–1916). The 1909 report, which provided summary data on earlier years, was used to definitively identify doctorate-granting institutions for the years up to 1909. The 1909 report excluded some institutions that had been included in earlier reports, presumably to correct for invalid information in prior years. Because some of the reported institutions had awarded very few doctorates and had done so sporadically, the list of pre-1920 awarding institutions was declared final only after a comparison with the early 1920s data in the DRF. Institutions that awarded doctorates in 1900–19 (according to Office of Education reports) and also in 1920–24 (according to the DRF) make up the pre-1920 list of doctorate-granting institutions. This group of institutions is discussed in chapter 5.

Employment commitment. Definite plans for any kind of employment other than a postdoctoral appointment for study or training are considered employment commitments. Military service counts as employment.

Field of doctorate. Field is the specialty field of doctoral degree as reported by the doctorate recipient or obtained from the institution's commencement program or graduation list.

There are about 280 fields on the SED Specialties List grouped under the following headings: agricultural sciences, biological sciences, computer and information sciences, education, engineering, health sciences, humanities (subdivided into history, letters, foreign languages and literature, and other humanities), mathematics, physical sciences (subdivided into astronomy, atmospheric science and meteorology, chemistry, geological and related sciences, physics, and miscellaneous physical sciences), professional fields (subdivided into business management and administrative services, communications, and other professional fields), psychology, and social sciences. The same list is used for reporting baccalaureate and master's degree fields as well as postdoctoral study and employment fields. The SED survey form and Specialties List can be found in appendix D of the annual Doctorate Recipients from United States Universities: Summary Report (NORC 1998–2002), which is available at http://www.norc.uchicago.edu/issues/docdata.htm.

This report categorizes the fields as science and engineering (S&E) or non-science and engineering (non-S&E) according to the scheme that NSF uses in its publications. Other agencies may classify the fields differently. The major difference between NSF's classification and those of other agencies is the exclusion of health fields from the S&E rubric; NSF places health fields within the non-S&E group, along with education, humanities, and professional fields. Other agencies include health fields with biological and agricultural sciences under the heading "life sciences" or with biological sciences alone under the heading "biomedical sciences."

Appendix A, table A-1, presents the number of doctorates awarded in each of the specialties, including those now obsolete, according to the NSF classification scheme. The table shows how fields have evolved over the years. Readers should be careful when interpreting time-series field data at the most disaggregated level. Specialties added over the years were reported in the general "other" category (e.g., other biological sciences) in earlier surveys or in a category that previously combined the new specialty with other specialties in the same general area (e.g., experimental/comparative/physiological psychology). The historical changes to the Specialties List are documented in Science and Engineering Doctorates: 1960–91 (NSF 1993) and in the subsequent series Science and Engineering Doctorate Awards (NSF 1997–2002). The 1960–91 report is out of print, but information will be provided upon request (contact Susan Hill, director, Doctorate Data Project, at sthill@nsf.gov or 703-292-7790).

Historically Black Colleges and Universities (HBCUs). HBCUs are the 105 institutions founded between the post-Civil War Reconstruction period and 1963 for the express purpose of educating blacks. Fifteen HBCUs, led by Howard University, awarded doctorates during the 20th century. For a list of HBCUs, see http://www.ed.gov/about/inits/list/whhbcu/edlite-list.html.

Primary source of support. For the periods 1980–81 and 1996–97, primary source of support pertains to the entire time a student was in graduate school. For the period 1998–99, this item covers doctoral study only. The SED questions on sources of support have undergone several changes in recent years. For example, in 1998 the number of source categories was reduced from 35 to 13. Sources are no longer identified by specific provider (e.g., agency, foundation, kind of loan), because students do not always know the actual provider of their funding. Only the mechanism of support (e.g., fellowship, research assistantship, loan) is now captured. Most of the current categories are aggregates of multiple categories that were on previous questionnaires. For example, the new category "research assistantship" (RA) combines five earlier categories—university-related RA, National Institutes of Health RA, NSF RA, U.S. Department of Agriculture RA, and other RA. Three new categories were added in 1998: "dissertation grant," "internship or residency," and "personal savings."

For this report, the mapping scheme developed by the current SED contractor was used to tie earlier data to the new categories in the 1998–99 surveys. Pre-1998 federal support categories that do not specify a mechanism (e.g., Veterans Administration, National Endowment for the Humanities, other U.S. Department of Health and Human Services, other Education, other federal) are now included with the new fellowship/scholarship category.

Race/ethnicity. The SED race/ethnicity question has undergone several revisions. In 1977 it was modified to correspond to a standard question format recommended by the Federal Interagency Committee on Education and adopted by the Office of Management and Budget for use in federally sponsored surveys. In 1980 the item was further revised in two ways: (1) the Hispanic category was subdivided into "Puerto Rican," "Mexican," and "other Hispanic" to provide more detail for users of the racial/ethnic data; and (2) respondents were asked to check only one race/ethnicity category. In 1982 the item was recast as two questions to capture ethnicity and race separately. Since then, respondents have been asked to indicate whether or not they are Hispanic and then check one of four race categories (American Indian/Alaskan Native, Asian/Pacific Islander, black, or white). In accordance with the standard practice for reporting SED results, doctorate recipients who reported being Hispanic, regardless of racial designation, were counted as Hispanic in this report. The remaining survey respondents were counted in their respective racial groups.

Regions in the United States. The 50 U.S. states and the District of Columbia are grouped into four major regions, as defined by the U.S. Census Bureau, for the purpose of reporting doctorate production by region.

Research doctorate. A research doctorate is any doctoral degree that (1) requires the completion of a dissertation or equivalent project of original work (e.g., musical composition) and (2) is not exclusively intended as a degree for the practice of a profession.

Although the most typical research doctorate is the Ph.D., more than 50 other kinds of degrees are covered in the SED. Not included in this definition are professional doctorates: Doctor of Medicine (M.D.), Doctor of Dental Surgery (D.D.S.), Doctor of Veterinary Medicine (D.V.M.), Doctor of Osteopathy (O.D.), Doctor of Pharmacy (Pharm.D.), Doctor of Psychology (Psy.D.), Juris Doctor (J.D.), and other similar degrees. For a complete listing of the kinds of research doctorates captured by the SED, see the inside of the back cover of the latest report in the annual Doctorate Recipients from United States Universities: Summary Report, which can be found at http://www.norc.uchicago.edu/issues/docdata.htm.

Sex. For most years since 1920, the doctorate recipient's sex was assumed to be male if not reported by the recipient or provided by the institution. The procedure was changed in 1991 to leave sex as missing if the information could not be obtained from the doctorate recipient or the institution and if the recipient could not be assumed with great certainty to be male or female based on his or her name. There are 1,886 Ph.D.s of undetermined sex in the DRF, all but two of them graduates in the 1990s. These individuals are excluded from all percentages based on recipients' sex shown in this report.

The number of male and female Ph.D.s graduating in the period 1900 to 1919 was obtained from table 28 in 120 Years of American Education: A Statistical Portrait (USED/NCES 1993). These data originally came from a series of annual reports published by the U.S. Office of Education (USEO 1869–1916) and a chapter in the Biennial Survey of Education in the United States (USEO 1918). Figures are not available for 1917 and 1919; data for those years were interpolated for the 1900 to 1999 trends shown in chapter 2.

Stay rate. Stay rate is the percentage of Ph.D.s with definite postgraduation plans who plan to stay in the United States.

The restriction on definite plans is necessary when examining long-term trends because, up to 1990, location was captured as part of "postdoctoral affiliation," which was generally completed by only those Ph.D.s with definite plans. In the 1990s the SED asked for location separately, resulting in more complete data on the intended locations of new Ph.D.s, whether or not they had commitments at graduation. The data from the 1990s show that a substantial number of non-U.S. citizens did not report commitments but did report intentions or aspirations to remain in the United States. Although there is no way to determine how many actually stayed on after graduation, it is fair to assume that a goodly number did. Table C-1 compares the 1995–99 aggregate data for non-U.S. citizens who reported definite postgraduation plans to stay in the United States (the population analyzed in chapter 6 and shown in table 6-2

and figures 6-8

and figure 6-9

) with the corresponding data for all non-U.S. citizens who reported location, including those who did not have commitments at the time they completed the SED.

Study commitment. Definite plans involving a postdoctoral fellowship, research associateship, traineeship, or any other postdoctoral study or training supported by an organization or the doctorate recipient are considered study commitments.

Time to doctorate. This report includes three different measures of time to receipt of the doctorate, which are reported as medians. Half of all Ph.D.s take more time than the median to complete their doctorate, and half take less.

Year of doctorate. The SED collects data for the academic year, which begins on 1 July of one calendar year and ends on 30 June of the next year. Academic years are identified in reports by the calendar year in which they end. For example, data reported as 1999 include all graduations from 1 July 1998 through 30 June 1999. Graduations that took place in the last six months of calendar year 1999 were part of the 2000 SED and are not included in this report.

The data for graduations from 1920 through 1957 were obtained from public sources, such as commencement programs, and were recorded in the DRF by calendar year. Because the second half of calendar year 1957 is part of the 1958 SED, an adjustment is required to make both years represent a full 12 months in tabulations. The standard procedure is to double-count the number of doctorates awarded in the last half of calendar year 1957. This six-month period was counted once in calendar year 1957 and once in academic year 1958 (the SED data collection period) for this report, but only for trends showing the 1950s as one or more data points. The total number of doctorates awarded in 1900–99 or 1920–99 reflects the actual number of doctorates awarded in those years, that is, with no double-counting of the number of doctorates awarded in the last six months of calendar year 1957.

Data Sources

The doctoral data in this report came from two original sources: U.S. Office of Education annual and biennial reports for the years 1900 to 1919, and the Doctorate Records File for the years 1920 to 1999 (including the results of the Survey of Earned Doctorates for the years 1958 to 1999).

U.S. Office of Education Reports

Data on the number of doctorates awarded from 1900 to 1919, in total and by sex, were obtained from 120 Years of American Education: A Statistical Portrait (USED/NCES 1993). These data came originally from a series of annual reports published by the U.S. Office of Education (USEO 1869–1916) and a chapter in the Biennial Survey of Education in the United States (USEO 1918). Figures are not available for 1917 and 1919.

Chapter 5 examines the role of institutions that awarded doctorates before 1920. The pre-1920 group of institutions was determined from the Office of Education reports. The 1909 report presented summary data for the years 1878–1909, excluding some institutions that had appeared in earlier reports. The assumption is that it was correcting for invalid data published previously. The 1909 report was used as the definitive source of doctorate-granting institutions up to 1909.

Doctorate Records File and Survey of Earned Doctorates

The Doctorate Records File (DRF) is a virtually complete data bank on more than 1.35 million doctorate recipients. For the years 1920–57, public sources, such as commencement programs and institution lists, provided limited information, mainly baccalaureate institution and year; doctoral institution, field, and year; and sex of recipient (which, if not obtained from the institution, was coded based on the recipient's name).

The DRF also houses the results of the Survey of Earned Doctorates (SED), an annual census of new doctorate recipients that has been conducted since the 1957–58 academic year (referred to as 1958 in published reports). The SED is sponsored by six federal agencies: the National Science Foundation (lead sponsor), the National Aeronautics and Space Administration, the National Endowment for the Humanities, the National Institutes of Health, the U.S. Department of Agriculture, and the U.S. Department of Education. The DRF also serves as the sampling frame for the biennial Survey of Doctorate Recipients, a longitudinal survey of science, engineering, and (in some years) humanities Ph.D.s who are employed in the United States.

Every year, the SED is distributed to all accredited colleges and universities that grant research doctorates (about 400). A few institutions refuse to participate, but it is known from the National Center for Education Statistics/U.S. Department of Education's Integrated Postsecondary Education Data System (IPEDS) Completions Survey that these institutions contribute minimally to the overall population of doctorates. The Completions Survey collects basic information on doctoral degrees from the institutions rather than from individual doctorate recipients.

Since 1994 more than 40,000 doctorates have been awarded annually. The annual numbers of doctorates reported in the results of the IPEDS Completions Survey are slightly higher than those in the SED. Differences can be attributed largely to the inclusion of nonresearch doctorates, primarily in the fields of theology and education, in the Completions Survey. The differences between the two surveys were fairly consistent from 1960 to 1999, with ratios of IPEDS-to-SED counts ranging from 1.01 to 1.06. Because a respondent to the SED may not classify his or her specialty exactly as reported by the institution in the Completions Survey, the difference in the number of doctorates for a given field reported by the two surveys may be greater than the difference for all fields combined.

The SED covers about 50 kinds of research doctorates. Most recipients earn the Ph.D. degree (85–89 percent annually since 1973, when kind of degree was first tracked). The Doctor of Education (Ed.D.) is the second most common degree, received by 7–11 percent of doctorate recipients each year from 1973 to 1999. Professional doctorates, including those in medicine, law, dentistry, veterinary medicine, osteopathy, and psychology, are not covered in the SED. The kind of professional doctorate and year of receipt, however, are captured for recipients of research doctorates who earned professional doctorates either before the research doctorate or concurrently.

Because the DRF is a census of individuals rather than degrees, only the first doctorate is entered into the database. Every year, the names and social security numbers of new doctorate recipients are compared with the same information on all earlier DRF records to ensure that there are no duplications in the database. Any records of second (or third) doctorates earned by a recipient are removed from the DRF, but hard copies of the survey forms for additional doctorates are retained. Data on predoctoral degrees of doctorate recipients also reflect the first degree at each level.

The SED cycle includes all graduations during the academic year (1 July to 30 June) and is identified by the year in which the cycle ends. Thus the 1999 SED collected data from doctorate recipients who graduated between 1 July 1998 and 30 June 1999. The graduate schools distribute the SED forms to students, who then complete the surveys and return them to the SED coordinator at their institution for transmittal to the survey contractor. Since 1997 the National Opinion Research Center of the University of Chicago has administered the SED for the sponsoring federal agencies. The National Research Council of the National Academy of Sciences administered the SED from its inception, in 1958, through the 1996 cycle.

Doctorate recipients provide information about their demographic characteristics, educational history from high school to doctorate, sources of financial support in graduate school (or in the doctoral program), debt status at graduation, and immediate postgraduation plans. Thanks to the cooperation of the graduate schools and the extremely high participation rates of doctoral graduates, the DRF is the richest source of doctoral data in the nation. Government agencies, academic institutions, and industry use the SED results to address a wide range of policy, education, and human resource issues. The authors of this report have strived to showcase the wealth of available data by presenting long-term trends when possible, and recent data when not, for nearly every variable in the DRF. More than 500 tables were generated, reviewed, and analyzed for this project, and data from many are displayed in figures and tables within the report. As a supplement to the printed volume, detailed trend tables showing doctoral awards by field of doctorate and by state and institution, baccalaureate institutions of Ph.D.s, and country of citizenship of non-U.S. citizen doctorate recipients, by visa status, are available on the NSF website at http://www.nsf.gov/statistics/nsf06319/.

Response Rates

The SED has enjoyed excellent response rates throughout its more than 40-year history. Both unit and item response rates have been very high and relatively stable since the first survey, in 1958.

Basic information on nonrespondents can be obtained from institutions or commencement programs, so records exist for all doctorate recipients. However, response to the SED is measured by the percentage of doctorate recipients who complete the surveys themselves (self-report rate), thereby providing details that are not available from any other source. The SED's goal is a stable self-report rate of 94–95 percent. This rate was achieved or surpassed in all but 9 of the 42 surveys processed between 1958 and 1999. The self-report rate dropped below target for the first time in 1986 and stayed below target through 1990. The 1991–95 surveys achieved the target level, but the self-report rate declined again in 1996–99. A little less than 92 percent of all doctorate recipients completed the survey in the last three surveys of the century, 1997–99.

Because records are constructed from public information for Ph.D.s who do not complete the SED questionnaire, certain items are available for all doctorate recipients: name, doctoral institution, field of doctorate, month and year of graduation, and kind of doctorate. The institution provides this information in its commencement program or graduation list.

A 95 percent item-response-rate target is set for eight critical items: date of birth, sex, citizenship, country of citizenship (for non-U.S. citizens), race/ethnicity, baccalaureate institution, baccalaureate year, and postdoctoral location. If missing, these items are followed up through letters to self-reporting respondents or, for Ph.D.s who did not complete questionnaires, through requests to institutions. The response rates for these items often exceed the overall self-report rate for the survey because of institutional responses and information on baccalaureate degrees available from commencement programs. Rigorous follow-up on critical items has been conducted since 1990. Follow-up requests for race/ethnicity, postdoctoral location, and country of citizenship (if foreign) were made for the first time in the 1990 SED, increasing the completeness of these items from that time forward. From 1990 to 1996, all critical items except postdoctoral location surpassed the 95 percent target. Response for every critical item except sex and foreign country of citizenship fell below target during subsequent years with transfer of the administration of the SED to a new contractor.

The target item response rate for all noncritical survey items is 90 percent. During much of the 1990s, most noncritical items either met or were within 2 percentage points of the target response rate. Fewer items attained a 90 percent response rate during the contractor transition period. Five noncritical items, if missing, are added to the follow-up requests for Ph.D.s missing critical items: birthplace, high school graduation year, high school location, master's degree institution, and year of master's degree. Throughout the SED's history, a few items have had, and will continue to have, lower response rates because they are not applicable to all individuals (e.g., master's degree information), or because they seem complex or confusing to some doctorate recipients (e.g., timelines from college entrance to doctoral graduation, sources of support).

Some items with below-target response rates in the first half of the 1990s surpassed the target in 1996, when the questionnaire was reformatted to be more respondent-friendly. Two items are particularly relevant to this report: (1) primary source of support, in which the 1996 response rate was 13.0 percentage points higher than in the previous survey, and (2) primary work activity after graduation, in which the response rate rose 6.5 percentage points. Moreover, response to these items held steady or increased during the transfer of the SED to a new contractor, despite a decrease in the overall self-report rate for the SED and decreases in response rates for many other items.

Although both unit and item response rates in the SED have been relatively stable through the years, fluctuations can affect data comparability. This is especially true for the items on citizenship and race/ethnicity, for which very small fluctuations in response may result in increases or decreases in counts that do not reflect actual trends. The percentages shown in the figures and tables in this report are based only on the number of doctorate recipients who responded to the applicable survey items (including some logical assumptions based on other items, as explained in the section "Definitions and Explanations") or for whom information was obtained from a public source. The overall response rate for any cross-tabulation of data is no greater than the lowest response rate for the items involved in the tabulation.

Table C-2 shows the nonresponse rates for the items analyzed in this report and displayed in figures and tables. For items covering a long time span, the overall nonresponse rate for the entire period is given, even though the data may be displayed annually or in 5-year periods in figures and tables. For items that are analyzed for only two or three select time periods, the nonresponse rate for each period is given.

Availability of SED Data

Results of the SED are published annually in Doctorate Recipients from United States Universities: Summary Report (NAS/NRC 1968–98, NORC 1998–2002), which covers doctorates in all specialty fields, and in Science and Engineering Doctorate Awards, which focuses primarily on science and engineering doctorates. Recent Summary Reports are available at http://www.norc.uchicago.edu/issues/docdata.htm. The Science and Engineering Doctorate Awards series (NSF 1997–2002) is available on the NSF website at http://www.nsf.gov/statistics/doctorates/.

Selected summary data from this survey are available on the NSF website noted above, and in the WebCASPAR database, which can also be accessed through the NSF website. Researchers interested in analyzing microdata may request access to restricted data through a licensing agreement with NSF. For more information about this survey, contact Susan Hill at sthill@nsf.gov or 703-292-7790.

References

National Academy of Sciences, National Research Council (NAS/NRC). 1968–98. Summary Report 1967…1996: Doctorate Recipients from United States Universities. Annual series of survey results from the Survey of Earned Doctorates, conducted by NAS/NRC under sponsorship of the National Science Foundation, National Institutes of Health, National Endowment for the Humanities, U.S. Department of Education, and U.S. Department of Agriculture. Washington, DC.

National Academy of Sciences, National Research Council (NAS/NRC). 1978. A Century of Doctorates: Data Analyses of Growth and Change. Prepared by L.R. Harmon. Washington, DC.

National Opinion Research Center (NORC). 1998–2002. Doctorate Recipients from United States Universities: Summary Report 1997…2001. Annual series of survey results from the Survey of Earned Doctorates, conducted by NORC for the National Science Foundation, National Institutes of Health, National Endowment for the Humanities, U.S. Department of Education, U.S. Department of Agriculture, and National Aeronautics and Space Administration. Chicago.

National Science Foundation (NSF). 1993. Science and Engineering Doctorates: 1960–91. NSF 93-301. Washington, DC.

National Science Foundation (NSF). 1997–2002. Science and Engineering Doctorate Awards: 1996…2001. Annual series. Arlington, VA.

U.S. Department of Education, National Center for Education Statistics (USED/NCES). 1993. 120 Years of American Education: A Statistical Portrait. Washington, DC.

U.S. Office of Education (USEO). 1869–1916. Annual Report of the United States Commissioner of Education. Washington, DC: U.S. Government Printing Office.

U.S. Office of Education (USEO). 1918. Biennial Survey of Education in the United States. Washington, DC: U.S. Government Printing Office.

Appendix C. Technical Notes

Definitions and Explanations