University Students' Misconceptions Concerning Osmosis and Diffusion

Abstract

The aim of the study is to determine the major and non-major biology students’ understanding of the concepts of diffusion and osmosis and to identify the points at which they have misconceptions by using a two-tier diagnostic test developed by Odom and Barrow (1995). The test, consisting of 12 multiple choice questions, was administered to 135 university students (79 majors and 56 non-majors). Each item was analyzed to determine the students’ understanding of, and identify their misconceptions about, diffusion and osmosis. For the first tier of the test, the range of correct answers was 53%-95% for the major and 42.7%-100% for the non-major biology students. However, when both tiers were combined this range was reduced to 27.8% - 88.6% for majors and 19.6% - 67.8% for non-majors. Analysis of the results revealed that neither major nor non-major students acquired a satisfactory understanding of these concepts and that they had a considerable degree of misconceptions concerning diffusion and osmosis.