Molecules Are Not Enough! Overcoming Students’ Overgeneralization Tendencies by Comparing and Contrasting


  • Adrian Zwyssig Institute for Research on Learning and Instruction, ETH Zürich, Clausiusstrasse 59, CH-8092 Zürich



Chemical Bonding, Chemistry education, Comparing and contrasting, Overgeneralization


Many students assume a molecular structure for all substances, even after being instructed on the topic. But why do students struggle to understand key concepts like chemical bonding? One of the reasons is students’ tendency to overgeneralize: Students wrongfully transfer characteristics from familiar (e.g., molecular substances) to lesser-known concepts (e.g., ionic compounds). In this article, possible reasons behind this commonly observed tendency are discussed and a possible didactical solution is proposed. Comparing and contrasting approaches increased students’ ability to distinguish between similar concepts in mathematics.[1] The method of comparing and contrasting is therefore applied by simultaneously introducing the three types of chemical bonding to effectively tackle students’ overgeneralization tendencies.