MULTIPLE CONCEPTIONS OF DISPLACEMENT VOLUME AS HELD BY LOWER SECONDARY SCHOOL STUDENTS

Abstract

In this study, the 7th grade lower secondary school students were asked to predict displaced volume as the response to a questionnaire on simple displacement volume tasks. The aim of the study was to ascertain whether the students hold multiple conceptions of displacement volume. The questionnaire was so designed as to direct students’ attention to the presence or absence of flow in the medium of displacement. The students were given a pair of two tasks, one of which being a “flow type task” that might give the students cues about the flow in the medium when an object was placed in it, while the other one being a “non-flow type task” in which the cues about the flow were made less salient by the use of non-flow type media and demonstration. The students’ responses obtained revealed a strong tendency that, when a flow type task was presented to the students as the first task and a non-flow type task as the second one, the first task elicited the students’ responses that predicted the displacement volume by the weight of the submerged body in a much higher frequency than the second task. But when the order of the presentation of those two types of tasks were reversed, the above tendency of students’ responses was also reversed. From these results, it can be concluded that many students at the lower secondary school level may hold two different conceptions of the displacement volume, i.e., one by the weight and the other one by the volume of submerged body, and it seems that they adapt either one of these to the displacement volume tasks depending on whether the cues about the flow in the medium are salient or not in the tasks.