Misconceptualization of the chemical equilibrium concept as revealed by different evaluation methods

Three evaluation methods were applied to examine students’ mastery of the ‘chemical equilibrium’ concept: (i) a school achievement test, (ii) a misconception test specifically designed to pinpoint possible misconceptions regarding eight central features (ideas) of the chemical equilibrium concept, and (iii) the free sorting of 18 concepts related to chemical equilibrium that served as a tool for cognitive structure mapping. An attempt was made to correlate the information derived from these methods. Students’ performance on the misconception test was poorer than on school tests. It was found that low achievements on the misconception test are reflected in the latent categories of the free sorting of the appropriate group. The reflection is judged by comparing the latent categories derived from the free sorting to theoretical groupings based on the relatedness of the 18 concepts to the eight features. The combination of the data from the evaluative methods can serve to provide teachers with useful information about students’ learning difficulties.