The Effect of Initial Pointer Position Relative to the Control on Directional Relationships in the Presence of Two Conflicting Stereotypes

Abstract

A variable liable to affect display-control relationships is treated in this article. It is shown that the strength of the stereotype known as Warrick's Principle, the expectation that a pointer will move in the same direction as that part of the control nearest to the display, is reduced as the pointer is set off to either side of the control knob. In an arrangement with the knob above a horizontal display this reduction may cause a reversal of an operator's expectation of directional relationship at a pointer position not very far from the knob. It is maintained, however, that this effect of pointer position is not likely to influence expectation in an unambiguous arrangement of display and control.