Investigating Greek students' ideas about forces and motion

Educational research has shown that high school and university students also follow the Aristotelian idea about motion; for example, a continuous action of a force is necessary to keep an object in motion. The survey presented in this article aims at a deeper investigation of secondary education students' ideas about the forces involved in objects moving under the sole influence of gravity. The main objectives are: (1) to investigate other ideas or difficulties, which intervene and determine students' mental models about motion and force, and (2) to reveal how the students in the sample are grouped according to their alternative conceptions. Our study has been mainly determined by the revision in Science Curriculum established in Greece three years ago. A survey has been administered to a total of 146 students (15-16 years old) attending six typical public high schools in Greece. The results presented show that the traditional instruction is pertinent while the approaches of the New Physics Curriculum have not been effectively expanded to the schools. The majority of the students exhibited the idea that "the original force is continuously exerted to the ball during its motion." On the other hand, multivariate analysis has identified three discernible groups of students which have exhibited a persistent and rather consistent approach: (1) An extended group of students having the above misconception, (2) a second group of students which, generally, responded correctly to the tasks, and (3) a third group of students, which ignored the presence of the gravitational force and/or believe that the action-reaction forces are both exerted to the ball during its motion.