
An idea we have since (in the area of adding zero-order control --- see Section \ref{calzeroordercontrol})had in this area that we believe would be worth further investigation is to map mouse displacement directly onto screen displacement. In Section \ref{pointercentrebest} we concluded that keeping the pointer locked in the centre of the screen while scrolling is the optimal method. In terms of zero order displacement, we think that moving the document across the screen by the same amount that the pointer \emph{would have} moved (had it not been kept in the centre of the screen) may be beneficial.

