Children's understanding of action lines and the static representation of speed of locomotion.

Children's understanding of the static representation of speed of locomotion was explored in 2 experiments. In Experiment 1, 20 7-year-olds and 20 9-year-olds drew pictures of 2 people walking and running at different speeds. Children then made judgments about pairs of unambiguous drawings of a person walking or running, as did a sample of 20 adults. The drawings varied according to whether action lines, background lines, or no lines were present. Children were asked to say which figure appeared to be moving faster. In Experiment 2, 20 7-year-olds, 20 9-year-olds, and 21 adults sorted ambiguous drawings of a person walking and running at different speeds. The pictures again contained action lines, background lines, or no lines. In the drawing task, children more frequently used page position and biomechanical information than action lines to represent fast and slow walking and running. In the judgment task, 7- and 9-year-olds offered equivalent judgments of action lines and background lines, whereas adults distinguished between these pictorial devices. In the sorting task, all subjects distinguished between action lines and background lines and judged that pictures containing action lines looked faster than pictures containing background lines and pictures without lines. Taken together, the results indicate that subjects' judgments were influenced by the form of locomotion and degree of ambiguity in the depicted events they saw. The findings are consistent with the view that different categories of pictorial devices exist, but the effectiveness of each device is contingent upon the perceiver's experience with it and the context in which it appears.