Towards a design methodology for adaptive applications

We describe an abstract architecture of adaptive applications, and indicate where we believe crucial design decisions must be made. We illustrate the use of the abstract model in the design and implementation ofan image proxy, and describe the studies required in determining the appropriate design points. In particular, even though adaptation to resource constraints is generally considered a systems probleu the adaptation is visible to the user in changes in utility, and so the user must be involved in designing the application. Finally, we discuss the politics that creep in when dwigners change the semantics of applications.