A time-use survey is a statistical survey that aims to report data on how people spend their time. If the necessary R&D coefficients cannot be derived from other surveys or administrative data, time-use surveys are the recommended method to derive the necessary information for estimating the R&D component of full-time equivalents (FTEs) and expenditures.
R&D surveys.
OECD (2015), Frascati Manual 2015: Guidelines for Collecting and Reporting Data on Research and Experimental Development.