Visual coherence and usability: a cohesion metric for assessing the quality of dialogue and screen designs

Interface design metrics help developers evaluate user interface quality from designs and visual prototypes before implementing working prototypes or systems. Visual coherence, based on the established software engineering concept of cohesion, measures the fit between the layout of user interface features and their semantic content. Visually coherent interfaces group semantically more closely related features together, enhancing comprehension and ease of use. Preliminary research using a scenario-based technique with built in validity checks found professional developers preferred more visually coherent designs and rated them easier to use, even when these departed from familiar dialogue conventions. Implications for design and further research are discussed.