On Indexing in Digital Libraries: Cooperation, Personalization, and Evolution

In databases and traditional paper documents, an index is often tightly coupled with the information resources being indexed. Digital libraries require a generalized notion of indexing that is suitable for distributed and heterogeneous collections. The main contribution of the generalization described in this paper is to introduce an additional intermediate layer between the navigational structure of the index and the information resources. This layer is populated by so called index elements providing decision support and access information concerning the underlying information resources. The generalized indexing concept provides a framework for the definition of generic services on indexes and their index elements. Different categories of services supporting the characteristics of the generalized concept are discussed in this paper with a special focus on the evolution of indexes, the personalization of indexes, and on cooperative work supported by indexes. As a concrete example for a cooperative service on index elements a tool for merging bibliographic index elements is introduced.