Comparison of the new RDA carrier and content typologies with end-user categorisations

The projected Resource Description and Access (RDA) standard, set to replace the Anglo-American Cataloguing Rules, aims to facilitate a more user-centred library catalogue display by breaking down the current General Material Designations (GMDs) and Specific Material Designations (SMDs) into two semantically distinct facets, one representing a resource's carrier, the other its content. As well as offering search limiting by these two facets, RDA-based catalogues could sort by either facet, and group results by the carrier and content categories for users to explore. However, although the theory behind the carrier and content typologies may be convincing, the sets of terms proposed to represent the various categories of carrier and content were not constructed through analysis of end-user classifications, nor have they been tested on end-users. One way of investigating how users categorise things, commonly employed by information architects, is the free-listing technique, in which participants are asked to list all the items in a particular domain. This technique was applied in a simple online survey that aimed to examine the nature and scope of carrier and content categorisation by visitors to a university library catalogue. The results indicate that user typologies may extend a lot further than the RDA categories, involving several other major facets, such as purpose, audience and extent. In common usage, the concepts of content and carrier, along with other facets, are very often combined, and an optimal catalogue search interface should do likewise.