Today’s rapidly expanding and dynamic information age coupled with users who are becoming more discerning about what information they want and when they want it poses a serious challenge to information retrieval systems in their attempt to match user’s information needs with information repositories. To date most research on information retrieval has concentrated on improving system effectiveness. However as the amount of online information and the number of users concurrently accessing this information continues to grow at an exponential rate the efficiency of information retrieval systems is now a core concern of information retrieval system developers. Users who were previously content to wait for information they needed are no longer willing or able to do so because in today’s dynamic information age the ‘shelf life’ of information is getting shorter and shorter. This results in increasing pressure on information systems to provide the ‘right’ information at the ‘right’ time. This research focuses on the improving the efficiency of information retrieval systems. To this end we have developed and implemented a number of techniques aimed at reducing system response time by reducing the amount of data processed in order to effectively respond to a user’s information need.