The classification research group and the theory of integrative levels

The Classification Research Group (CRG), formed in the UK in 1952, has been one of the most significant contributors to classification research and theory in the latter half of the 20th century. The theoretical work of the Group has involved the study of facet analysis, relational operators, and the theory of integrative levels. The CRG opposed the traditional top-down approach to classification, whereby areas of knowledge are predetermined and then broken down into their constituent elements. The CRG was interested in first piecing together individual elements and then determining the areas of knowledge they form. The CRG looked towards the theory of integrative levels to provide them with the basis for this bottom-up approach to classification. This paper explores and evaluates the CRGÍs efforts to apply the theory of integrative levels to the construction of bibliographic classification systems