Abstract
The perceptual error characteristics when judging the position of index line were compared between horizontal and vertical presentations in order to provide basis for designing displays that took perceptual error characteristics into account. In the vertical judgment, the index line was presented horizontally. The index line was presented vertically in the horizontal judgment. The index line appeared randomly on a position between divisions 0 and 10. The experimental factors were direction of judgment (horizontal and vertical). The task was to judge the position using an integer from 0 to 10. Different error characteristics were identified for both vertical and horizontal judgments. For the vertical judgment, when the index line located left or right of the scale 5, it tended to be recognized as scale 4 or 6. On the other hand, such a tendency was not observed for the horizontal judgment. As a whole, the error when judging the position of horizontal index line (vertical judgment) was less than that when judging the position of vertical index line (horizontal judgment). The results would be applicable to the presentation of bar graphs. When using bar graphs, the one which requires us vertical judgment is more desirable than that which requires us horizontal judgment.
