Publication metrics are used in the analyses of the fields of science in a number of contexts. Many national evaluations of fields of science use metrics to evaluate, for example, the number of publications, citation impact and interdisciplinarity in the field. The field of science is often included in analyses of research organisations or countries as a factor through which publishing activities are analysed. In many university rankings, it is possible to examine universities by field of science. The field of science is also a key factor in overall evaluations of university research.
When analysing or evaluating the publishing activities of different fields of science through the means of publication metrics, or when using the field of science as a variable in analyses of units such as research organisations or countries, it is important to take into account the differences in publishing and citation practices across different fields of science.