Visualisation of usability data: measuring task efficiency

Usability testing is a method of evaluating the usability of a given product in a given environment. Formal usability testing is an empirical method that requires the design of a formal usability experiment that is undertaken under controlled conditions in a usability laboratory. Formal usability testing produces actual measures of usability in terms of task effectiveness and efficiency. Existing software tools for visualising the results of formal usability testing are, however, limited and inadequate. This paper will discuss the typical components of such usability data and the design of a multiple view visualisation system to effectively view task efficiency that was based on recent guidelines for multiple view systems.