The application of thesauri in digital libraries is seriously constrained by the manual nature of current thesaurus maintenance mechanism which cannot keep up with the rapid evolvement of knowledge.

• 摘要词表和分类法是传统纸质文献环境下最重要的知识组织工具。它的更新和维护一直依靠手工进行。这限制了它在数字图书馆和网络信息环境下的应用。