Abstract
Previous research by Attneave, Palmer, and others has examined why stimuli such as triangles are seen to point in one direction rather than another, but little research has been done on what makes a given stimulus point at all, i.e., convey directional information. Arrows, Vs and triangles are often used to indicate direction, but it is not apparent why they are more commonly used than are other, similar, stimuli such as checkmarks, Ts, Us, or Ys. Arrows, Vs, triangles, Ts, Ys and checkmarks all contain V-intersections, where the vertex could define pointing direction. Additionally, an arrow is symmetric whereas a checkmark is asymmetric; thus, symmetry along the axis in the direction of pointing may be important. The present work is a first attempt at a systematic catalog of perceptual properties of shapes as they relate to pointing strength and direction. Arrow-like shapes were systematically manipulated along several dimensions, including the angle of the chevron's vertex, the ratio of the width of the chevron to the length of its line, and the position of the chevron along the line. Participants judged perceived pointing strength and direction, and they also performed speeded navigation tasks requiring use of these pointers. The results show large differences in the effectiveness of different pointers in both judgment and performance tasks. In addition to providing insights into the perception of pointing, the present work may be valuable for the design of effective directional indicators for use on roadway signs and computer navigation systems.