Formal models for user interface design artefacts

Abstract

There are many different ways of building software applications and of tackling the problems of understanding the system to be built, designing that system and finally implementing the design. One approach is to use formal methods, which we can generalise as meaning we follow a process which uses some formal language to specify the behaviour of the intended system, techniques such as theorem proving or model-checking to ensure the specification is valid (i.e., meets the requirements and has been shown, perhaps by proof or other means of inspection, to have the properties the client requires of it) and a refinement process to transform the specification into an implementation. Conversely, the approach we take may be less structured and rely on informal techniques. The design stage may involve jotting down ideas on paper, brainstorming with users etc. We may use prototyping to transform these ideas into working software and get users to test the implementation to find problems. Formal methods have been shown to be beneficial in describing the functionality of systems, what we may call application logic, and underlying system behaviour. Informal techniques, however, have also been shown to be useful in the design of the user interface to systems. Given that both styles of development are beneficial to different parts of the system we would like to be able to use both approaches in one integrated software development process. Their differences, however, make this a challenging objective. In this paper we describe models and techniques which allow us to incorporate informal design artefacts into a formal software development process.

Information engineering for developing and testing coherent, integrated and context-dependent user interfaces

“…For example, Duke et al (1999) showed that formal specification techniques based on set theory can clarify what information can or should be presented to users and to specify the effect user actions should have. Bowen and Reeves (2008) proposed to formalize the meaning of user-centered design outcomes in a presentation model based on set theory. This approach ensures correct and robust implementation of design guidelines describing UI properties or design rules, such as rules for consistency.…”

Reasoning About Interactive Systems in Dynamic Situations of Use

“…The first are the sets of properties of the interactive systems and devices which are known to exist in a given location. For our previous work with safety critical medical devices we typically already had initial models (based on the presentation models of (Bowen and Reeves, 2008)) from which we could automatically extract widget and interaction information. As the interactive systems we are now dealing with are not safety critical, this is less likely to be the case and so we manually create the sets of properties of interest.…”

UI-design driven model-based testing

“…We create a link between the formal specification of the system and the user interface design by creating presentation models and presentation and interaction models (PIMs) [BR06], BR08a]. The presentation model gives a description of the interface designs based on the interactive elements (widgets) of the design.…”

“…The combination of the system specification and the UI models (presentation models, PIM and PMR) provides a formal description of the entire system. We have previously shown how we can use this information as a way of ensuring correctness of the the proposed system [BR08a] and also as the basis for refinement [BR08b]. In this paper, however, we will use the models to derive tests which can then be run on an implementation of the system.…”

“…In previous work we have developed models for UIs [BR08a,Bow08] which are based upon design artefacts created as part of a user-centred design (UCD) process. In this paper we investigate whether we can use these models as the basis for model-based testing for interactive systems.…”