A well designed user interface (UI) should be transparent, allowing users to focus their mental workload on the task at hand. We hypothesize that the overall mental workload required to perform a task using a computer system is composed of a portion attributable to the difficulty of the underlying task plus a portion attributable to the complexity of operating the user interface. In this regard, w... read moree follow Shneiderman's theory of syntactic and semantic components of a UI. We present an experiment protocol that can be used to measure the workload experienced by users in their various cognitive resources while working with a computer. We then describe an experiment where we used the protocol to quantify the syntactic workload of two user interfaces. We use functional near infrared spectroscopy, a new brain imaging technology that is beginning to be used in HCI. We also discuss extensions of our techniques to adaptive interfaces.read less
Hirshfield, Leanne M., Erin Treacy Solovey, Audrey Girouard, James Kebinger, Robert J.K. Jacob, Angelo Sassaroli, and Sergio Fantini. "Brain Measurement for Usability Testing and Adaptive Interfaces." Proceedings of the 27th International Conference on Human Factors in Computing Systems - CHI 09 (2009). doi:10.1145/1518701.1519035.