Abstract. Ubiquitous computing requires a multitude of devices to have access to the same services. Abstract specifications of user interfaces are designed to separate the definition of a user interface from that of the underlying service This paper proposes the incorporation of interaction style into this type of specification. By selecting an appropriate interaction style, an interface can be better matched to the device being used. Specifications that are based upon three different styles have been developed, together with a prototype StyleBased Interaction System (SIS) that utilises these specifications to provide concrete user interfaces for a device. An example weather query service is described, including specifications of user interfaces for this service that use the three different styles as well as example concrete user interfaces that SIS can produce.
IntroductionThe increasing availability of personalized and ubiquitous technologies leads to the possibility that whatever the device-to-hand is, it becomes the way to access services and systems. Therefore, interfaces to services must be designed for a variety of different types of device from desktop systems to handheld or otherwise portable devices. Different styles of interaction often suit different devices most effectively. While the appearance of ubiquitous devices has brought forth a proliferation of innovative interactive techniques, the broad categories and aspects of style as, for example, identified by Newman and Lamming [1] can still be applied. While a keymodal interface may be appropriate for a mobile telephone, with its limited screen and restricted keypad, a direct manipulation (DM) interface may be appropriate for a device based around touch / pen interactive techniques, such as current models of palmtop or tablet PCs. Typically in such situations a different low-level interface will have to be designed separately for each device. It is possible that several interaction styles may have to be supported for different users or parts of the system on the same device. As new technologies evolve to meet the demands of ubiquitous computing additional styles will emerge. Style-specific design considerations normally take the form of guidelines, heuristics or ad-hoc rationalizations by designers [2]. Designs to support many devices may be facilitated by incorporating interaction style explicitly into an implementation. In this paper we demonstrate that incorporating style-level descriptions into a model of a user interface can give more flexibility than forcing a single user interface model on a heterogeneous selection of devices. This paper is concerned with an approach in which interaction with a service is bound to the features of the platform through a mediating style description. The aim is to support an interface that is appropriate given the technological constraints or opportunities afforded by the platform. In section 2 the approach to the style-based interaction system is contrasted with other approaches to platform independent service...