High-Level User Interface Models for Model-Driven Design of Context-Sensitive User Interfaces

Abstract

The usage of multi-purpose electronic devices that are available to the mass public has increased significantly. The size of these devices has caused a shift in the places where these devices are used. The small size of devices such as personal digital assistants and smart phones does not require anymore that a user sits down at a desk to do tasks such as searching information over the internet or managing appointments, sending messages, . . . Many users, however, do not only use this mobile device to accomplish these tasks but prefer the usage of a larger computing device, such as a laptop or a personal computer. This often means that a user has to learn different interaction methods and different user interface structures. At the same time, communities are increasingly independent of the location of their participants; most of the communication is done through communication devices. When in the past people came together in a local pub, to enjoy entertaining activities, today more and more people do not necessarily meet at a common physical place, but rather meet online. This has increased the interest of the telecom industry to not only make entertainment more interactive, but also to introduce the social components into digital broadcasts. They want to extend the social impact that online chatservices have to other fields. Participatory television should be for watching television in group, what internet chat is for face-to-face conversations. Because the common meetingplace is gone, participants do not necessarily have to be in front of a television at home, but can be on the road, also requiring some level of context-sensitivity. In this dissertation, some of the challenges that these new types of applications pose to design of their user interfaces are addressed, more specifically the integration of context sensitivity in general and presence for participatory television. The premise for all the work presented in this dissertation is that in order to produce interactive applications that work well in these demanding circumstances, a well-structured and systematic approach is to be taken, such as a model-based or model-driven design methodology. For this design methodology, we analysed the current approaches for their support of context-sensitiveness and came to the conclusion that currently context-sensitiveness and context influences are not extensively covered, especially at higher levels of abstraction. A first contribution of our work is the integration of context-sensitivity in the user-task model. This work is based on one of the most popular notation for user-task modeling, the ConcurTaskTrees notation. We extended this notation to include context tasks resulting in a notation that was a strict superset of the ConcurTaskTrees notation, the Contextual ConcurTaskTrees. After task specification, the actual modeling of the interactive application may be started. This modeling is often divided into two parts; user interface modeling and modeling of the application core. This dissertation focuses on the former, but wants to ensure that the results can be used in a unified approach to the design of interactive systems. Indeed, it is recognized that usability problems often are also caused by problems in the design of the application core or its binding with the user interface. At this level, we introduce context-sensitivity in high-level models expressed using the Unified Modeling Language (UML). For this purpose a profile is presented that extends the UML with the necessary constructs. While these models can provide good foundations, they are not always the most suitable notation in all situations. One of these situations is where the designers are very unlikely to have knowledge of the UML and deal with problems whose solution cannot be easily covered by the UML. The design of participatory television events is one of those situations. Participatory television also has a prominent place for context sensitiveness; awareness of the other users. In a last contribution, this dissertation describes a language that allows to describe such events. In the dissertation, the relation of the constructs with those present in the UML will also be discussed.