Total intramural expenditure on R&D performed during a specific reference period, broken down by the fields of research and development. The fields included are:
1. Natural sciences
2. Engineering and technology
3. Medical and health sciences
4. Agricultural and veterinary sciences
5. Social sciences
6. Humanities and the arts.
Adapted from OECD (2015), Frascati Manual 2015: Guidelines for Collecting and Reporting Data on Research and Experimental Development.