Given that the digital library field is still quite new, it seems strange to be talking already about enhancing digital libraries. However, in this fast-moving environment, the initial digital libraries resulting from digitization projects, or even virtual collections, are being enhanced as user expectations and technology capabilities allow. In the midst of this furious activity, it is valuable to analyze users’ needs and interests and then to identify KOSs that can be used to enhance the digital library.
Knowledge organization systems refer to a range of traditional and nontraditional systems for the organization of knowledge. The systems have been developed in numerous environments outside the traditional library environment, including those of A&I services, publishers and professional organizations, and corporations. Examples exist in many disciplines and for many target audiences.
Knowledge organization systems can enhance the digital library in a number of ways. They can be used to connect a digital library resource to a related resource. The related information may reside within the KOS itself or the KOS may be used as an intermediary file to retrieve the key needed to access it in another resource. A KOS can make digital library materials accessible to disparate communities. This may be done by providing alternate subject access, by adding access by different modes, by providing multilingual access, and by using the KOS to support free text searching.
A well-planned infrastructure for KOSs is required. This includes the resources, processes, and policies for analyzing user needs; locating KOSs to answer these needs; and acquiring, implementing, and maintaining the KOS.
Traditional and nontraditional KOSs provide an opportunity to extend the boundaries of the digital library. By going beyond the initial organization of the digital library, digital librarians can use the network environment to provide additional value to its users.