In a German out-of-school laboratory, 293 medium-achieving 10th-grade students participated in a lesson unit about gene technology. They were divided into two groups (I-1, I-2), both of which followed the same hands-on lesson procedure. Students within I-2 were additionally confronted with alternative conceptions to central issues of the specific…

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…