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Toward Usability Problem Identification Based on User Emotions Derived from Facial Expressions

Tracking down usability problems poses a challenge for developers since users rarely report explicit feedback without being asked for it. Hence, implicit feedback represents a valuable information source, in particular for rapid development processes with frequent software releases. Users' emotions expressed by their facial expressions during interactions with the application can act as the source of such information. Recent development in consumer hardware offers mechanisms to efficiently detect facial expressions. We developed a framework for interactive mobile applications to harness consumer hardware camera technology for facial feature extraction to enable emotion detection following the facial action coding system. In a study with 12 participants, we evaluated its performance within a sample application that was seeded with usability problems. A qualitative analysis of the study results indicates that the framework is applicable for detecting user emotions from facial expressions. A quantitative analysis shows that emotional responses can be detected in three out of four cases and that they relate to usability problems. We conclude that, in combination with interaction events, the framework can support developers in the exploration of usability problems in interactive applications.