The domain is the domain(s) of human knowledge covered by the publication, such as natural sciences or humanities.
Our top-level domains are taken from Gordana Dodig-Crnkovic (2002), Scientific Methods in Computer Science, Proc. Conf. for the Promotion of Research in IT at New Universities and at University Colleges in Sweden. However, we subsume her "Culture" domain into "Humanities". We defined the lower level categories ourselves based on the subject matter of the articles. Some sub-domains belong to multiple top-level domains; for example, we classify Category:Computer_science as a sub-domain of Category:Logic_and_mathematics, Category:Natural_sciences and Category:Social_sciences