Knowledge-based query optimization in information retrieval

A personal information system can not only help users managing their personal documents, but also act as an intelligent agent to search and collect useful documents from existing information system including Internet on behalf of users. A knowledge-based approach to information retrieval is used. This approach is based on a dual document model that consists of a document type hierarchy and a folder organization. A document type hierarchy describes the conceptual structure of the documents. The folder organization, serves as document filing model, emulates the real world structure for organizing and storing documents in an office environment. Users can search documents based on knowledge about the documents on different level of abstraction. This paper presents a knowledge-based query optimization algorithm for efficiently and effectively narrowing down search space. An intelligent folder reorganization agent and a guided search agent are proposed.