Usability error classification: Qualitative data analysis for UX practitioners

Usability evaluations generate large amounts of poorly structured qualitative data, but traditional methods of analysis are often impractical for use by industry practitioners. To address this, we developed a classification of usability issues covering cause, effect, task impact and business impact. In a design project, this has several applications, such as a) enabling practitioners to analyze qualitative data quickly and reliably; b) ensuring that findings can be systematically compared across studies; c) presenting results to clients in terms of potential business impact and its causes; and d) offering recommendations to designers in terms of design errors and their cost. We continue refining the model as we test it in our projects.