In our increasingly interconnected and interdependent information society, the Quality of Service (QoS) and Quality of Data (QoD) experienced by the users determine the success or failure of any mission-critical, data-driven application. In this talk, we illustrate the trade-offs between QoS and QoD, and present algorithms to control this trade-off, while providing quality guarantees to the users.
We use three different data management environments as our domain examples: (1) dynamic, database-driven web sites, (2) sensor networks, and (3) mission-critical, realtime database systems.
We show that in all cases, users can benefit greatly by controlling the trade-off between QoS and QoD. Finally, we present Quality Contracts, a unifying framework for specifying user preferences over QoS and QoD.