Comparison of three dwell-time-based gaze text entry methods

Gaze text entry (GTE) with use of visual keyboards displayed on computer screen is an important topic for both the scientists dealing with the gaze interaction and potential users i.e. people with physical disabilities and their families. The most commonly used technique for GTE is based on dwell-time regions, at which the user needs to look longer to activate the associated action, in our case - entering the letter. In the article, we present the results of tests of three GTE systems (gaze keyboards) on a sample of 29 participants. We compare the objective measures of usability, namely the text entry rate and the number of errors, as well as subjective ones, obtained using SUS questionnaire. Additionally, two similar keyboards based on the ‘Qwerty’ buttons layout were compared in terms of time to the first fixation and its duration in the areas of interest (AOI) corresponding to the visual buttons. One of these gaze keyboards, the so called ’Molecular’ one, contains dynamic elements that have been designed and implemented in our laboratory, and which aim is to support the search for buttons by increasing the size of buttons with suggested letters, without significant change of their positions.