Quality‐controlled subject gateways: definitions, typologies, empirical overview

“Quality‐controlled subject gateways” are Internet services which apply a rich set of quality measures to support systematic resource discovery. Considerable manual effort is used to secure a selection of resources which meet quality criteria and to display a rich description of these resources with standards‐based metadata. Regular checking and updating ensure good collection management. A main goal is to provide a high quality of subject access through indexing resources using controlled vocabularies and by offering a deep classification structure for advanced searching and browsing. This article provides an initial empirical overview of existing services of this kind, their approaches and technologies, based on proposed working definitions and typologies of subject gateways.