Usability testing activities have numerous benefits in theory, yet they are often overlooked or disregarded in practice. A testing paradigm which yields objective, quantitative results would likely lead to more widespread adoption of usability evaluation activities. Total-Effort Metrics is such a novel framework. This paper describes a usability study conducted using a total-effort metrics approach. In this study, subjects interact with three interfaces which have varying element layout proximities. The time and effort measures of time-on-task, total keystrokes, correctional keystrokes, saccade amplitude (point-to-point eye movement) and gaze-path traversal are recorded and analyzed. The findings of the study demonstrate a correlation between the intrinsic effort of an interface and its usability as predicted by extant interface layout guidelines.
Liam Feldman, Carl J. Mueller, Dan E. Tamir, Oleg