A case study of on-screen prototypes and usability evaluation of electronic timers and food menu systems

Ubiquitous computing in domestic products, although allowing smarter products, can increase the complexity of interfaces that the end user has to face. This case study is an evaluation of an on-screen prototype of a cooker timer and food menu system. The techniques used to evaluate the prototype included questionnaire, user trial, System Usability Scale questionnaire (Brooke, 1996), observation, interview, repertory grid, Hierarchical Task Analysis (Kirwan & Ainsworth, 1992), and Task Analysis for Error Identification (Baber & Stanton, 1991, 1996; Stanton & Baber, 1998). From the usability evaluation a simplified interface was designed that will be taken forward and reevaluated in the future. Issues raised in the case study were first that of increased complexity allowed by increased levels of processing power, and second that of on-screen prototypes and the difference between interacting with traditional desktop computing applications as opposed to a physical product. We highlight in the conclusion that there is a need for those involved in development of on-screen and physical prototypes to work with those involved in human factors and usability to ensure a usable end product.