DEEP: Design-Oriented Evaluation of Perceived Usability

Existing perceived usability questionnaires detect the appearance of usability issues rather than the underlying design generating those issues. This limits the capability of existing instruments to directly inform design recommendations. To address this problem, a usability questionnaire structured around the analytical composition of the design was created and validated. A four-stage process was followed. First, 3 usability experts refined 54 questions from highly cited usability questionnaires and structured them around 6 design dimensions. Second, 12 raters scored the questions by their relevance to assess usability. Third, questions and dimensions were then improved through exploratory and confirmatory factor analysis (N?=?196) and, fourth, further enhanced through confirmatory factor analysis (N?=?362). The result is DEEP, a 19-question usability questionnaire based on 5 main design dimensions (content, information architecture, navigation, layout, and visual guidance). DEEP can be used to capture detailed usability feedback that more directly relates to specific aspects of design requirements.