I've got a check for pass, and an x for fail. Both controls are positioned next to each other on the right side of the screen. The preferred action is pass so it should be the most natural gesture. My question it come before or after the less favorable control (x/fail)? (if it occurs after it will be very close to the edge of the screen).
This issue becomes more apparent on mobile devices. For shorter thumbs the furthest right position feels most natural, however when tested with a larger thumb it seems more comfortable to have it in the left position.
My question then becomes is there a syntactically correct way to display the controls: and should the preferred control be displayed before or after the less-favorable control?