Bibliometrics is the generic term for data about publications. This includes data on the numbers of articles and publications produced, classified under different headings such as author, institution, subject area, country, in order to construct simple indicators of productivity for academic research. It also includes more sophisticated techniques such as the number of times an article is 'cited', or mentioned, in other publications. Bibliometrics have been used to derive indicators of quality by many countries and organisations. They were explored as a potential element for use in the UK-wide Research Excellence Framework.