Moving Ahead with Peephole Pointing: Mo...

Head-worn displays (HWDs) are now becoming widely available, which will allow researchers to explore sophisticated interface designs that support rich user productivity features. The available field of view (FoV) on these devices is a hardware limitation that determines the available space for virtual content. In a large virtual workspace, this limitation will cause objects to often be located outside of the available viewing area Object selection requires users to first locate an item using head motion before making a selection. However, FoV varies widely across different devices, with an unknown impact on interface usability. We present a user study to determine the effects of FoV size on object selection in this two-step selection process, using a CAVE environment to simulate the FoV restriction of stereoscopic HWDs. We compare two different input methods, direct pointing, and raycasting, and fit our results against two-component models previously proposed for ‘peephole pointing’ in large virtual workspaces on mobile devices. We find a very strong fit in this new HWD context, comparable to the prediction accuracy in the original mobile context, and much more accurate than the traditional Fitts’ law model. We detect an advantage of direct pointing over raycasting, particularly with small targets. Moreover, we find that this advantage of direct input diminishes with decreasing FoV.