Abstract
In this study, fifth grade children (n = 67) solved word problems using the knowledge structure "duration = temporal stopping point minus temporal starting point" to compare the time two different objects moved. Before and after learning this knowledge structure, participants viewed an image on a screen that depicted two cars traveling in the same direction. The children were asked to judge which car had started earlier and stopped earlier, and which car had run for a longer time. A second sample of fifth graders (n = 70) made spatial judgments in the same way. The results showed that it was very difficult to judge durations of the two moving cars, even after learning the knowledge structure. For fifth graders it seemed to be a little easier to judge distances of the two moving cars by using the knowledge structure "distance = spatial stopping point minus starting point."
