When evaluating scientific performance based on publications, the most common evaluation criteria are the number of publications and citations, and the quality of publication channels. Different disciplines are looked at separately, as they differ in terms of publishing and citing practices and also the speed of obsolescence of scientific knowledge and literature.
Measuring the publishing productivity of different disciplines is complicated. The amount of work required varies. Also the appreciation of publication types within different disciplines can be different. One also needs to consider the research resources e.g time and money.
Co-authoring affects also effects on the publishing productivity of the discipline. Joint publications, which are typical in medicine, can be calculated in several different ways when looking at the publishing activities of a research unit. One way is to add to the publications of a whole research unit all publications that have at least one research unit member as a co-author. Joint publications can also be divided on the basis of the number of authors and affiliations that have been involved in them.