A hands-on instructional approach with medium-achieving 10th-grade students (N = 294) successfully demonstrated the achievement of a conceptual change. Two teaching variations were applied (I-1, I-2), both dealing with a hands-on gene technology lesson in an out-of-school laboratory. I-2 additionally confronted the participants with alternative…

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…