Test and evaluation of distributed information system networks

As information services become increasingly ubiquitous, and are being charg ed for, users are demanding the ability to choose the quality of an informa tion service based on its cost. In this environment, delivering the right i nformation to the right user at the right time, and with appropriate qualit y, is the challenge. In addition, resource optimizations must be performed to the degree possible. In this paper we introduce the concept of informati on quality based system evaluation. The key contribution is a framework in which user/application needs for information quality can be quantified in t erms of rigorously defined metrics, existing systems can be evaluated again st these metrics, and the tradeoffs between information quality and its cos t of provisioning can be examined. Further, this provides an approach to de veloping information quality aware policies and mechanisms for the system. This framework has been partially validated by applying it to the provision ing of continuous media services, i.e., audio and video, in a distributed e nvironment. This paper presents the case study in detail. Finally, the pape r outlines a research program in the area of information quality based syst em evaluation.