Abstract

The Journal of .General Psychology, 1949, 41, 47-65. ESTIMATIONS OF DISTANCE ON POLAR COORDINATE PLOTS AS A FUNCTION OF THE SCALE USED*l Psychological Laboratory, The Johns Hopkins University N. R. BARTLETT, J. D. REED, AND G. DUVOISIN A. THE PROBLEM This paper concerns the r6le of the language of the scale which observers employ in estimating the position of a mark on a polar coordinate display. Previous determinations have shown the accuracy of distance judgments to be a function of the relative position of the stimulus. The question at stake about such functions is whether they reflect a common perceptual tendency in distance estimations, or whether instead they are artifacts of the number scales in which the judgments were expressed. The problem, was undertaken as a part of a broad program of research dealing with visual communication on radar display devices. A common type of radar display, the polar coordinate plot, is a circular map with concentric circles marked off on the map to denote distances from the center. The task of the radar operator is to estimate the position of small marks on the display. This paper concerns judgments of that type, but presumably the findings can be