Reports descriptive study concerning student understanding of isomers. Sample of 7,441 senior high school students completed tests which contained 12 questions on isomerism. Results indicate students are inclined to restrict their concept of isomerism to compounds belonging to the same class. There was no evidence students expected molecular…

Interviews were conducted with grade 10 students (n=34) who had received 4 years of physics instruction. Interview's focus was to understand students' responses from their point of view. The results of the study confirm and deepen findings from other studies concerning students' severe difficulties in learning the energy concept, the particle…