Keeping it real : the potential for accessible mixed-reality usability testing environments

This body of research contributes to design praxeology: the study of process and methodology with the intention to enhance the designer's experience of the human-centred design process by means of validating an optimum usability testing environment for recreating the context of use early in the design process. Usability testing will frequently make the difference between an excellent product and a poor one. Moreover, in certain fields such as medical device development or training, the defence field or the automotive industry, such testing can literally be the difference between life and death. Unfortunately, design teams rarely have the luxury of either time or budget to usability test every aspect of a design at every stage, and so knowing where and when to devote time to testing, and the fidelity required for accurate results, are all critical to delivering a good result. This thesis introduces research aimed at defining the optimum fidelity of mixed-reality usability testing environments. It aims to develop knowledge enabling the optimization of usability testing environments by balancing effort vs reward and thus developing critical and accurate data early in the design process. This research also seeks to validate the findings of an optimum environment in a final study and highlight the significance of early usability testing in a simulated context of use. Testing in a traditional laboratory setting brings advantages such as the ability to limit experimental variability, control confidentiality and measure performance in detail. Its disadvantages over 'in the wild' or field studies approaches tend to be related to ecological validity and the small but vitally important changes in user behaviour in real-life settings. Virtual reality and hybrid physical-virtual testing environments should theoretically give designers the best of both worlds, finding critical design flaws cheaply and early. However, many attempts have focused on high-fidelity, technology-rich approaches that make them simultaneously more expensive, less flexible and less accessible. Additionally, the design literature does not take due account of computer science and psychology when dealing with recreating environments. The final result is that they are less viable and hence somewhat counter-productive. This thesis presents the results of testing at a variety of fidelity levels within a mixed-reality testing environment, and offers a contribution to new knowledge in determining how usability testing can be maximized to recreate context of use environments early in the design process. The findings recommend the use of recreated environments throughout the design process complemented by field/in-the-wild testing once the product is of high fidelity.