 In this way it is not necessarily a kind of indexing based on user studies.Only if empirical data about use or users are applied should request oriented indexing be regarded as a user-based approach.Rowley & Hartley (2008, p. 109) wrote "In order to achieve good consistent indexing, the indexer must have a through appreciation of the structure of the subject and the nature of the contribution that the document is making to the advancement of knowledge within a particular discipline".