Distributed digital library architecture: the key to success for distance learning

Cost cutting and personnel restructuring are forcing organizations to make difficult decisions on where to spend money. Among the areas hit hard by budget cuts are education and training. Academic, industrial, and governmental institutions are all seeking means to leverage technology to improve the timeliness, efficiency, and standardization of their required training. One way to extend budgets while continuing to deliver training is by constructing distributed digital libraries. A distributed digital library consists of material on separate machines connected via a network. The challenge of managing this information is deciding how to store the information and how users will connect, search, and retrieve the material. One method, the monolithic library, forces all user interactions through a single, controlling node of the library network. Another is called the distributed library, which hides the actual server architecture by allowing the user to interact with whichever library node is nearest to him. Using the model of the U.S. Army's Army Training Digital Library as an example, this paper will discuss challenges and solutions to indexing, searching, and retrieving material from globally distributed digital libraries. In particular, this paper will compare the costs and benefits of using a monolithic library structure with that of a distributed digital library.