In the 1970s and 1980s, forms of user-based and cognitive approaches to knowledge organization came to the forefront as part of the overall development in library and information science and in the broader society. The specific nature of userbased approaches is their basis in the empirical studies of users or the principle that users need to be involved in the construction of knowledge organization systems. It might seem obvious that user-friendly systems should be designed on user studies or user involvement, but extremely successful systems such as Apple’s iPhone, Dialog’s search system and Google’s PageRank are not based on the empirical studies of users. In knowledge organization, the Book House System is one example of a system based on user studies. In cognitive science the important WordNet database is claimed to be based on psychological research. This article considers such examples. The role of the user is often confused with the role of subjectivity. Knowledge organization systems cannot be objective and must therefore, by implication, be based on some kind of subjectivity. This subjectivity should, however, be derived from collective views in discourse communities rather than be derived from studies of individuals or from the study of abstract minds.