Display characteristics, network Quality of Service, and the user's current task all exhibit a wide range of variation when users interact with mobile and ubiquitous devices. It is desirable to enable applications to adapt to these variations. The user's experience in interacting with the application can be significantly enhanced by adapting the data presented. However, we find that naive degradation of data can quickly result in an unacceptable presentation. In this paper we present a means of describing compound documents and preferences according to the semantics of the data, and an algorithm for performing a selection amongst the offered data based on these descriptions. Our model of the user's preferences is more descriptive than most common specifications used for Webbased applications. These have been implemented for a map viewing application, along with application level network resource management. We present test results for adapting to network bandwidth and a...