Discrimination between design errors and user errors by binomial test
Lajos Izsó · Behaviour and Information Technology · 2000
In laboratory usability studies, error collecting and analysis are frequently used methods of software evaluation and usually are capable of revealing the most conspicuous design deficiencies, if there are any. In certain cases, however, it is hard if not impossible to distinguish accidental user errors from systematic errors attributable to design failures without a careful statistical hypothesis testing. An appropriate, additional statistical analysis of the distribution of observed errors along the steps of the standard tasks could add further useful information to the obvious results of the study. For this purpose a simple binomial model is proposed, which proved to be applicable in a case study: by the help of this model it was possible to discover some further design failures in addition to the already obvious ones.