Web information systems co-design

ABSTRACT

The tutorial will address the various aspects of web information systems (WISs) such as purpose, usage, content, functionality, context, presentation. Starting from the strategic characterisation of a WIS, i.e. the very general question what the WIS is about, we first explore the kind of content that is to be presented in the WIS, and the kind of functionality, with which this content can be accessed, customised to the needs of particular WIS users, and updated. We then explore the modelling of users (or actors) of the WIS, their goals, and the tasks that have to be performed to reach these goals, and general rules for the formation of the WIS presentation.

On a high-level of abstraction co-design emphasises storyboarding, which concerns the usage of the intended system. It consists of three interconnected parts: the modelling of the story space, the modelling of the actors, i.e. clases of users, and the modelling of tasks. We present a modelling language for storyboarding, and briefly discuss an algebraic approach to reason about storyboards emphasising the personalisation with respect to preference rules, and the satisfiability of deontic constraints. For the former one starting from the algebra that was used to specify story spaces, we will now show that this algebra can in fact be represented as a Kleene algebra with tests (KATs), which enables a simple form of system personalisation through effective term rewriting. We will further demonstrate how deontic constraints impact on the personalisation, then outline how this can be used to reason about tasks. In a third step we address pragmatics of storyboarding emphasising life cases, user models and context models that permit a deeper understand of what users actually understand the system to be used for. They further provide aids for practical storyboarding.

On a lower level of abstraction the co-design approach emphasises content and functionality modelling. This level takes a deeper look into the scenes of the storyboard and links them with the necessary database support. Each scene will be supported by a view on some underlying database that will result in the content to be presented. With respect to functionality operations are added to the views. These operations have to be understood as detailed specifications of the actions that appear in the storyboard. In a last step we introduce three more extensions to the views. The first one is hierarchies, which enable more coarse or more detailed presentation of information. The second extension addresses adaptivity to technical restrictions such as channel bandwidth or end-devices. The third extension deals with presentation options using knowledge about cognitive models and facts from art to bring strategic considerations on ambience into the conceptual model.