Knowledge and strategies used by adolescents to compare duration of movement by two objects.

This study investigated the knowledge and strategies used by senior high school students to compare durations of movement by two objects. The developmental process during adolescence was also examined by comparing the results with those published for Grade 7 to Grade 9 students and university undergraduates. A cathode-ray tube monitor was used to present images of two cars traveling in the same direction for various durations and distances. 30 Grade 12 students were asked to identify which of the cars had traveled for a longer duration and why. Analysis suggested that the strategies develop during adolescence in a sequence. Initially, comparison of durations was based on the relative distance traveled by the two cars. Then the comparison was based exclusively on knowledge that "duration = temporal starting point- temporal stopping point." Finally, the two types of knowledge were used appropriately according to the characteristics of the specific task.