TABLE 7-6Number of Ph.D.’s in 2006 NRC Study Compared with Ph.D.’s in NSF Doctorate Record File

Broad FieldDRF 20062006 NRC Study% in Study
Agricultural sciences1,4701,14778
Biological and health sciencesa5,7375,54397
Physical and mathematical sciences7,2837,09297
Social and behavioral sciencesb7,7835,99777
 Total minus psychology30,34628,28393

Note: The DRF responses are from a questionnaire administered to students at the time of graduation. The NRC data are from responses to the program questionnaire. The timing of the answers to the two questionnaires may account for discrepancies. The NRC questionnaire was answered in 2007, for 2005–2006 graduates, whereas the NSF questionnaire covered Ph.D.’s awarded in 2005–2006.


Integrated biological science, which appears in the NRC biological and health sciences taxonomy (Appendix B), is not a DRF field. The 867 Ph.D.’s from these programs were probably spread across the NSF biological sciences taxonomy.


Universities were asked to exclude programs in clinical and counseling psychology. The exclusion of these programs accounts for the low rate of coverage in the social and behavioral sciences. The coverage rate for all social science fields, excluding psychology, is 89 percent.

From: 7, The Data and Principal Findings

Cover of A Data-Based Assessment of Research-Doctorate Programs in the United States
A Data-Based Assessment of Research-Doctorate Programs in the United States.
National Research Council (US) Committee on an Assessment of Research Doctorate Programs; Ostriker JP, Kuh CV, Voytuk JA, editors.
Washington (DC): National Academies Press (US); 2011.
Copyright © 2011, National Academy of Sciences.

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