Put Buttons and Menus at the Edge of the Screen
The reason for this is mostly ergonomic: It is easier to move the mouse to a target at the edge of the screen than to one somewhere in the middle. At the edge of the screen, the boundary of the display acts as a visual, or actual, bumper to quick motions. Finding a target in the middle of the screen requires slowing down to keep from overshooting. This takes more time, and uses mental energy inappropriately. Also, as noted previously, primary informationregardless of ergonomicsshould be located near the optical center, with secondary information at the edges: A reader's eyes are most likely to follow a path from the center outward. Finally, for psychological continuity, orienting information should be placed at the top or the bottom of the screen, depending on whether it relates to the preceding or following screen, respectively.