II-33b: Shares of Interdisciplinary Dissertations Completed in Various Secondary Fields, by Primary Field of Dissertation,* 2011–2013
* Primary dissertation field is that reported by dissertation author. The secondary "field" may be another discipline within the same field (e.g., a humanities Ph.D. might report the primary field of their dissertation as history and the secondary as philosophy). Life sciences includes agricultural sciences and natural resources; biological and biomedical sciences; and health sciences. Physical sciences includes mathematics and computer and information sciences. Social sciences includes psychology.
Source: National Science Foundation, National Center for Science and Engineering Statistics, Survey of Earned Doctorates (SED; a custom tabulation of SED data was prepared for the Humanities Indicators by NORC at the University of Chicago).
To determine the levels of interdisciplinary work among new doctoral recipients, staff at NORC at the University of Chicago drew on two items in the Survey of Earned Doctorates (SED). The first of these asked each new PhD to “choose the code that best describes the primary field of your dissertation.” The second item asked, “If your dissertation was interdisciplinary, list the name . . . of your secondary field.” (For a complete list of the field and discipline response options, see pages 6 and 7 of the 2012–2013 SED questionnaire).