This publication is based on data from two annual federal surveys. Data on bachelor's and master's degrees and data on doctoral degrees in engineering technologies were collected from institutions of higher education by the Integrated Postsecondary Education Data System Completions Survey, conducted by the National Center for Education Statistics, U.S. Department of Education. Data on research doctoral degrees in all fields except engineering technologies were collected by the Survey of Earned Doctorates, a universe survey of individual doctorate recipients sponsored by the National Science Foundation (NSF) and five other federal agencies.

These data cover earned degrees conferred from 1966 to 2012 in the aggregate United States, which comprises the 50 states, the District of Columbia, and the U.S. territories and outlying areas (American Samoa, the former Canal Zone, Guam, the Northern Mariana Islands, Puerto Rico, the U.S. Virgin Islands, and the Trust Territory of the Pacific Islands). Degree data are compiled for a 12-month period, from July of one year through June of the following year. For convenience, degrees in a given July-through-June period are referred to by the year in which the period ended (e.g., 2012 means the 12-month period beginning 1 July 2011 and ending 30 June 2012).

This publication focuses on degrees in science and engineering (S&E) fields. Where appropriate, the bachelor's and master's degree data are reclassified to be consistent with the NSF field of degree taxonomy. For example, in the data tables, engineering technology degrees and degrees in the health and medical sciences are not included in totals for S&E fields but are provided as separate data tables, as are data on first professional degrees.

The time series for degree data may be affected by changes in definitions, instructions, and field classifications, including the introduction of new specialties. In this report, data for earlier years are presented as consistently as possible with the current field classification system, the 2010 Classification of Instructional Programs (CIP). See appendix B, "Classification of Fields of Study," for complete information on the field classifications used in this report. See also the section "Field Classification Schemes" in appendix A, "Technical Notes," for a discussion of the impacts of field classification changes on counts of bachelor's, master's, and doctoral degrees in six engineering fields and two social sciences fields.