From the standpoint of satisfying human's information needs, the current digital library (DL) systems suffer from the following two shortcomings: (i) inadequate high-level cognition support; (ii) inadequate knowledge sharing facilities. In this article, we introduce a two-layered digital library architecture to support different levels of human cognitive acts. The model moves beyond simple information searching and browsing across multiple repositories, to inquiry of knowledge about the contents of digital libraries. To address users' high- order cognitive requests, we propose an information space consisting of a knowledge subspace and a document subspace. We extend the traditional indexing and searching schema of digital libraries from keyword-based to knowledge-based by adding knowledge to the documents into the DL information space. The distinguished features of such enhanced DL systems in comparison with the traditional knowledge-based systems are also discussed.
- DB-IR: INFORMATION RETRIEVAL