Means for Resource discovery enable a user searching for a digital resource to actually find and retrieve it. Retrievability is a paramount attribute of any information provider. Its service is a more valuable source if it offers convenient methods to locate digital objects. Assisting the user in this way forms an integral part of the provision of access to digital information.
Discovery services act as the intermediary between the users and the information providers. Like library catalogues or bibliographic records, they represent the access point to the resources seeked. By support of descriptive metadata the digital facilities can offer a highly efficient interface. Catching the important aspects of a document, metadata minimises the amount of data to be searched. Additionally, it is much smaller as the whole collection item and can, hence, be stored in a central database or in another way that offers fast retrieval.
Obviously, the metadata has to be created at an earlier stage, preferably at ingest of the document into the archive. Thereby, either automatic or manual processes have to compile the predefined elements of the metadata set. Full-text indexing and the extraction of specific information from resources with a defined structure is performed by automatic methods. Initially, the resources have to be organised and the metadata has to be created manually, however, if human evaluation is required.
Which elements the metadata set should consist of, which aspects to be extracted from the document are relevant, is an integral decision to take and must be tailored to the purpose of the service and the user's needs.