There is currently great interest in building information gathering agents that provide integrated access to data from a number of distributed Web sources. Some of the prominent research projects in this area include The Internet Softbot, Information Manifold, InfoMaster and InfoSleuth. A critical problem faced by such agents is a high query response time, due to the fact that a lot of data from Web sources has to be retrieved, extracted, and integrated to answer queries. The aim of this work is to develop an approach for improving query response time in information agents. The resulting system is being developed as part of the Ariadne project (Knoblock et al. 1998).