A method for assessing the usability of an on screen display for a brain-computer interface

Brain-computer interfaces (BCIs) aim to provide a mechanism bywhich individuals with severe forms of paralysis can communicate their wishesto others or gain control over devices in their environment. This paperdescribes the evaluation of an interface designed for use with BCI, which isdedicated to providing a flexible and extensible framework for controllingmultiple devices within a domestic environment. A structured format forassessing the usability aspects of this interface is presented. Thegoal-question-metric (GQM) approach derived from measurement in softwareengineering was used, providing a mechanism that can be readily adapted toassess other interfaces in assistive technology. The assessment was based oninteraction of five participants currently using assistive technology whoprovided an initial representation of the target user group. Their input, inaddition to guidance from a lead user, was used to influence subsequent designchoices and directions and highlight the importance of user-centred designwithin BCI development.