S&E Degrees: 1966–2006
Appendix A. Technical Notes
Bachelor's and Master's Degree Data
Data from the Integrated Postsecondary Education Data System (IPEDS) Completions Survey were used to report numbers of bachelor's and master's degrees. The Completions Survey, conducted by The National Center for Education Statistics (NCES), U.S. Department of Education, collects data annually on all degrees conferred between 1 July of one year and 30 June of the next year from the universe of accredited institutions of higher education in the 50 states, the District of Columbia, and the U.S. territories and outlying areas (American Samoa, the former Canal Zone, the Northern Mariana Islands, Puerto Rico, the U.S. Virgin Islands, and the Trust Territory of the Pacific Islands). Institutional representatives submit data to the IPEDS online collection system. The survey 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. Data are collected according to sex of recipient and field of study. For more information on IPEDS, see http://nces.ed.gov/IPEDS/about/.
In 2006 the universe of institutions granting degrees at the level of bachelor's or higher was 2,690. Each year between 1966 and 2006, institutional response rates to the survey have exceeded 99%. Imputations for nonresponse were based on the previous year's response for an institution. For bachelor's and master's degree data, the percentage of degrees imputed rounds to zero.
Because the data in this report include those for institutions in the U.S. territories, they may differ from numbers published by NCES that relate to the 50 states and the District of Columbia and their field groupings. Data on degrees by field of study were collected according to the NCES Classification of Instructional Programs (CIP) (see appendix B). Information on the CIP is available at http://nces.ed.gov/pubs2002/cip2000/.
Doctoral Degree Data
Data on doctoral degrees were derived from the Survey of Earned Doctorates (SED), funded jointly by the National Science Foundation (NSF), the National Institutes of Health, the U.S. Department of Education, the U.S. Department of Agriculture, the National Aeronautics and Space Administration, and the National Endowment for the Humanities.
The SED is a voluntary survey that collects information annually for the period of 1 July of one year through 30 June of the next from all persons who have fulfilled the requirements for a research doctorate at a U.S. institution. SED data were preferred over Completions Survey data for doctoral degrees because data provided by individuals are more specific with respect to the field of specialization and are less prone to errors in data reporting and data entry than are data provided in aggregates by institutions. Furthermore, self-reported data provide almost complete coverage for data by field and sex of individual recipients, whereas institutional data are subject to imputation for nonresponse.
The survey forms are sent to all accredited U.S. doctorate-granting institutions for distribution by the graduate deans to all research doctorate recipients as they complete degree requirements. The survey collects demographic data, such as the student's sex, citizenship, and racial/ethnic group; educational history, including field of degree; sources of graduate student support; employment status during the year preceding receipt of the doctorate; postgraduation plans; and background on parents' education.
Approximately 92% of doctorate recipients complete and return the survey forms. For nonrespondents, commencement programs, graduation lists, and other similar public records allow construction of partial records, limited to field of study, year of doctorate, doctoral institution, and sex, which are added to the data file. Consequently, for the variables used in this report, there is almost complete coverage. Data are updated annually from completed survey forms submitted belatedly by previous nonrespondents; therefore, data on doctorates are subject to revision and may differ slightly from reports published earlier. For more information on the SED, see http://www.nsf.gov/statistics/doctorates/.
Field Classification Schemes
Four field classification systems were used during the 1966–2006 period covered by this report. The current classification scheme for the CIP is used for the Completions Survey; it and corresponding fields for the SED are provided in appendix B, "Classification of Programs." Data for earlier years are presented as consistently as possible with the current classification schemes.
Note that the data in this report are grouped into the science and engineering categories used by NSF. Data on engineering technology degrees and degrees in health/medical fields are not included in the science and engineering totals here. Therefore, data in this report may differ from those in reports published by the U.S. Department of Education. However, separate tables containing engineering technology, health medical fields, as well as first professional degrees, are included in this report.
 A research doctorate is defined by the SED as (1) making an original contribution of knowledge to a field (typically by means of a dissertation) based on research; and (2) not primarily intended for the practice of a profession. Doctoral degrees such as the PhD, DSc, and research EdD are covered by this survey; professional degrees (e.g., MD, DDS, DVM, JD, PsyD, and DMin) are not.