Effects of Perceptual Variations on Number Comparison Tasks

Abstract

Three types of number-comparison tasks were administered to 502 children (in the age range between four years, and six years and ten months). The tasks consisted of two-choice tasks and multiple-choice in which the density of the elements (dots) was manipulated, i.e., in one condition the elements stood far apart and for the other condition the distance between the elements was small, but within each of these conditions the elements were evenly spaced. The multiple-choice tasks were divided into tasks with constant target size (i.e. the area of all the elements of each set was identical) and tasks without constant target size. It was shown that two-choice tasks were easier than multiple-choice tasks controlling for chance responding. The density manipulation produced a strong effect, i.e., tasks in which the elements were placed closely together were more difficult than tasks in which the elements were spaced far apart. Multiple-choice tasks with constant target size were easier than tasks without constant target size. This is a noteworthy finding, because the opposite result might be expected. Since in tasks without constant target size a correct judgment could be based on either the relative numerosity or on redundant non-numerical cues (e.g. amount of target size, brightness, background area)), these tasks might be considered easier than tasks with constant target size in which the influence of these cues was reduced. However, our results can be interpreted that by using constant target size another cue has been introduced, because an accurate judgment can be made now by simply relying on the size of the target.