Refinement for user interface designs

Formal approaches to software development require that we correctly describe (or specify) systems in order to prove properties about our proposed solution prior to building it. We must then follow a rigorous process to transform our specification into an implementation to ensure that the properties we have proved are retained. Different transformation, or refinement, methods exist for different formal methods, but they all seek to ensure that we can guide the transformation in a way which preserves the desired properties of the system. Refinement methods also allow us to subsequently compare two systems to see if a refinement relation exists between the two. When we design and build the user interfaces of our systems we are similarly keen to ensure that they have certain properties before we build them. For example, do they satisfy the requirements of the user? Are they designed with known good design principles and usability considerations in mind? Are they correct in terms of the overall system specification? However, when we come to implement our interface designs we do not have a defined process to follow which ensures that we maintain these properties as we transform the design into code. Instead, we rely on our judgement and belief that we are doing the right thing and subsequent user testing to ensure that our final solution remains useable and satisfactory. We suggest an alternative approach, which is to define a refinement process for user interfaces which will allow us to maintain the same rigorous standards we apply to the rest of the system when we implement our user interface designs

QOC-E: A mediating representation to support the development of shared rationale and integration of Human Factors advice

Designing and manufacturing medical devices is a complex and specialist effort. Throughout the process, there is an opportunity to consult across those involved in various aspects of development (for example Human Factors (HF), Human Computer Interaction (HCI), Design and Manufacture). Developers report difficulties in this area, speaking of isolated team members and organizational / cultural barriers. We illustrate the use of a mediating representation (Questions, Options, Criteria and Evidence – QOC-E) that promotes shared reasoning and can be used to capture design rationale. Application is demonstrated using an illustrative example involving the specification of a number entry mechanism. The benefits of the QOC scheme include making tacit reasoning explicit, articulation of trade-offs, traceability, allowing compartmentalization of the design and avoidance of fixation in any one particular area. Downsides include the fact that the representation may require prohibitive amounts of effort to maintain or fail to scale to large or complex systems. These issues are discussed and directions for further investigation outlined

Investigation of a Novel Formal Model for Mobile User Interface Design

Mobile user interfaces are becoming increasingly complex due to the expanding range of functionalities that they incorporate, which poses significant difficulties in software development. Formal methods are beneficial for highly complex software systems, as they enable the designed behaviour of a mobile user interface (UI) to be modelled and tested for accuracy before implementation. Indeed, assessing the compatibility between the software specification and user requirements and verifying the implementation in relation to the specification are essential procedures in the development process of any type of UI. To ensure that UIs meet users‘ requirements and competences, approaches that are based on interaction between humans and computers employ a variety of methods to address key issues. The development of underlying system functionality and UIs benefit from formal methods as well as from user-interface design specifications. Therefore, both approaches are incorporated into the software development process in this thesis. However, this integration is not an easy task due to the discrepancies between the two approaches. It also includes a method, which can be applied for both simple and complex UI applications. To overcome the issue of integrating both approaches, the thesis proposes a new formal model called the Formal Model of Mobile User Interface Design (FMMUID). This model is devised to characterise the composition of the UI design based on hierarchical structure and a set theory language. To determine its applicability and validity, the FMMUID is implemented in two real-world case studies: the quiz game iPlayCode and the social media application Social Communication (SC). A comparative analysis is undertaken between two case studies, where each case study has three existing applications with similar functionality in terms of structure and numbers of elements, functions and colours. Furthermore, the case studies are also assessed from a human viewpoint, which reveals that they possess better usability. The assessment supports the viability of the proposed model as a guiding tool for software development. The efficiency of the proposed model is confirmed by the result that the two case studies are less complex than the other UI applications in terms of hierarchical structure and numbers of elements, functions and colours, whilst also presenting acceptable usability in terms of the four examined dimensions: usefulness, information quality, interface quality, and overall satisfaction. Hence, the proposed model can facilitate the development process of mobile UI applications

Exploring Design Options Rationally

. This paper describes a design technique for interactive systems that allows designs to be specified and refined formally, using a notation based on Action Systems. The rationale underlying the choices made by designers is recorded in a style based on the "Questions, Options, Criteria" notation. The means of capturing formal specifications and the reasoning behind design decisions are presented as parts of a uniform framework; a formal account is given of how design options satisfy criteria and how design options can be combined to answer larger design questions. 1 Introduction The use of formal specification techniques and development methods has been widely advocated as a means of meeting the levels of integrity demanded of computer-based systems. For many interactive systems, the satisfaction of overall objectives and requirements of functionality and dependability depends crucially on the system's usability. For this reason, formal specification and development techniques are mak..