Clumping towards a UK National catalogue?

This article presents a clumps-oriented perspective on the idea of a UK national catalogue for HE, arguing that a distributed approach based on Z39.50 has a number of attractive features when compared with the alternative physical union catalogue model, but also noting that the many difficulties currently associated with the distributed approach must be resolved before it can itself be regarded as a practical proposition. It is suggested that the distributed model is sufficiently attractive compared to the physical union model to make the expenditure of additional time, effort and resource worthwhile. 'Dynamic clumping' based on collection level description and other appropriate metadata is seen as the key to user navigation in a distributed national catalogue. Large physical union catalogues like COPAC are assumed to have a role, although updating difficulties and the lack of circulation information may limit its scope.