Students' explanations of biological phenomena are frequently characterized by disconnects between levels and confusion of levels. The purpose of this research is to investigate the effects of a hands-on lab activity that aims at fostering the ability to reason across levels. A total of 197 students (18 years of age) participated in a randomized,…

"Non-native organisms are a major threat to biodiversity". This statement is often made by biologists, but general conclusions cannot be drawn easily because of contradictory evidence. To introduce pupils aged 11-14 years to this topic, we employed an educational program dealing with non-native animals in Central Europe. The pupils took…