276 ;;Quote: for precision tasks, the preferred hand acts within the dynamic reference frame formed by the nonpreferred hand; e.g., threading a needle is more difficult if the needle is fixed

276+;;Quote: nonpreferred hand holds doll to dynamically define the frame of reference; relative to hand position instead of a fixed frame, screen, or center point

Guiard ;;Quote: for human bimanual gestures, the left hand defines the spatial reference, specializes in slow, large-scale movements, and precedes motion of the right hand

282 ;;Quote: for difficult, two-handed tasks with tool and target, preferred grip is clearly better than reversed grip; insignificant for easy task

287 ;;Quote: with a two-handed interface, users can easily express complex spatial relations; e.g., cut relative to view

287+;;Quote: users effortlessly move their hands relative to one another, but they require conscious effort to move relative a fixed 3D space

291 ;;Quote: for distance, bimanual condition twice as accurate as unimanual condition; angle about the same; bimanual, unimanual better than reverse order