In interactive systems, the term rendering applies to any form of communication directed from the application towards the users. The present paper deals with the specification of rendering, and its relationship with the formal specification of the dialogue between application and user. We first present a taxonomy of rendering according to its function in the application. We briefly recall the basics of the ICO formalism, which is used for the formal specification of the application. We then present a case study illustrating how various categories of rendering are taken into account in the ICO formalism. Lastly, we show how mathematical analysis can be performed on the ICO models to verify predictability properties of the interactive system. 1. Introduction Although a lot of work has recently been devoted to the formal specification of interactive systems, the presentation component has received much less consideration than the dialogue component. However, as stated in [10], "arguments...

This paper is introducing a graphical notation for specifying concepts (i.e. window, window transition, basic operations and generic operations) as well as issues involved in a mid-level dialogue model. The basic version of this notation is firstly introduced and manipulated. It is then theoretically explored to investigate what are the possible cases generated by this notation. As not all of these theoretical cases are likely to occur or to be usable enough to warrant a final UI, a few guidelines is provided to show how theoreti- cal cases can be restricted to usable ones. The basic nota- tion is then refined to incorporate the specification of widgets holding the capabilities to manage the dialogue at that level. A set of four dialogue attributes affecting the selection of this type of widget is defined and illustrated on a small case study.

The development of complex, multi-user, interactive systems is a difficult process that requires both a rapid iterative approach, and the ability to reason carefully about system designs. This thesis argues that a combination of declarative prototyping and formal specification provides a suitable way of satisfying these requirements. The focus of this thesis is on the development of software tools for prototyping interactive systems. In particular, it uses a declarative approach, based on the functional programming paradigm. This thesis makes two contributions. The most significant contribution is the presentation of FranTk, a new Graphical User Interface language, embedded in the functional language Haskell. It is suitable for prototyping complex, concurrent, multi-user systems. It allows systems to be built in a high level, structured manner. In particular, it provides good support for specifying real-time properties of such systems. The second contribution is a mechanism that allows a formal specification to be derived from a high level FranTk prototype. The approach allows this to be done automatically. This specification can then be checked, with tool support, to verify some safety properties about a system. To avoid the state space explosion problem that would be faced when verifying an entire system, we focus on partial verification. This concentrates on key areas of a design: in particular this means that we only derive a specification from parts of a prototype. To demonstrate the scalability of both the prototyping and verification approaches, this thesis uses a series of case studies including a multi-user design rationale editor and a prototype data-link