RU/VH (Research Universities – very high research activity)
RU/H (Research Universities – high research activity) (UH here)
DRU (Doctoral/Research Universities)

Level of research activity. Doctorate-granting institutions were assigned to one of three categories based on a measure of research activity. It is important to note that the groups differentiate solely with respect to level of research activity, not quality or importance.

The analysis examined the following correlates of research activity: research & development (R&D) expenditures in science and engineering (S&E; “science and engineering” is defined by NSF to include the social sciences); R&D expenditures in non-S&E fields; S&E research staff (postdoctoral appointees and other non-faculty research staff with doctorates); doctoral conferrals in humanities fields, in social science fields, in STEM (science, technology, engineering, and mathematics) fields, and in other fields (e.g., business, education, public policy, social work). These data were statistically combined using principal components analysis to create two indices of research activity reflecting the total variation across these measures (based on the first principal component in each analysis).

One index represents the aggregate level of research activity, and the other captures per-capita research activity using the expenditure and staffing measures divided by the number of full-time faculty whose primary responsibilities were identified as research, instruction, or a combination of instruction, research, and public service. The values on each index were then used to locate each institution on a two-dimensional graph. We calculated each institution’s distance from a common reference point, and then used the results to assign institutions to three groups based on their distance from the reference point. Thus the aggregate and per-capita indices were considered equally, such that institutions that were very high on either index were assigned to the “very high” group, while institutions that were high on at least one (but very high on neither) were assigned to the “high” group. Remaining institutions and those not represented in the NSF data collections were assigned to the "Doctoral/Research Universities" category.