Sample survey
From Bilat-Wiki
Translations missing. Please help us to translate this therm |
NSF2: Every four out of five years, the R&D expenditures survey is conducted as a sample survey where only 25 percent of institutions in the probability category and all institutions in the certainty category are surveyed (as opposed to a full population survey which is conducted every fifth year and all institutions in the certainty and probability categories are surveyed). Data for institutions not sampled during a sample survey year are estimated through imputation.