Information Retrieval II

Abstract

This chapter extends the basic ideas of information retrieval in several directions. The emphasis moves away from remote services and bibliographic databases, towards full-text retrieval application, set up by large organisations for their own purposes. A short case study will describe how one company acquired, selected and indexed data for its own internal requirements. General-purpose commercial software is normally used to implement such systems, and an account will be given of two different packages and the facilities they provide for setting up and querying databases; these will be linked, respectively, to the use of parallel processing hardware, and integration with conventional relational database technology. The final topic to be discussed is text compression: as longer texts are stored it may become very desirable to reduce the database size as much as possible, and so this is an appropriate point to give an overview of the relevant techniques.

“To your text, Mr. Dean! to your text!”

Queen Elizabeth I