An Empirical Study of Relationships Between Traditional Usability

Task performance data and subjective assessment data are widely used as usability measures in the human-computer interaction (HCI) field. Recently, physiology has also been explored as a metric for evaluating usability. However, it is not clear how physiological measures relate to traditional usability evaluation indexes. In this paper, we investigate the relationships among three kinds of data: task performance, subjective assessment and physiological measures. We found evidence that physiological data correlate with task performance data in a video game: with a decrease of the task performance level, the normalized galvanic skin response (GSR) increases. In addition, physiological data are mirrored in subjective reports assessing stress level. The research provides an initial step toward using physiology as a complementary or an independent usability measure for HCI evaluation