Towards knowledge-based digital libraries

From the standpoint of satisfying human's information needs, the current di gital 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 arc hitecture to support different levels of human cognitive acts. The model mo ves beyond simple information searching and browsing across multiple reposi tories, to inquiry of knowledge about the contents of digital libraries. To address users' high- order cognitive requests, we propose an information s pace consisting of a knowledge subspace and a document subspace. We extend the traditional indexing and searching schema of digital libraries from key word-based to knowledge-based by adding knowledge to the documents into the DL information space. The distinguished features of such enhanced DL syste ms in comparison with the traditional knowledge-based systems are also disc ussed.