Positioning Glass:

The physical position of the display on a monocular OST-HMD in relative to our eye is an important factor of the performance and usability in dual-task scenarios. We investigated 9 different display positions in a modern dual-task scenario with 27 participants. The experiment-involved participants responding to 3 different types of notifications displayed on the HMD while performing a visually intensive primary task. We found that although the notifications at the middle and bottom center positions were noticed quicker, the top and the peripheral positions were more comfortable, unobtrusive, and preferred. In particular, middle-right strikes the best balance between performance and usability in the dual-task scenario we studied. Our findings and discussions demonstrated the need for further work and a more rigorous investigation in dual-task scenarios with characteristics dissimilar to ours.