Two studies comparing students’ explanations of an oxidation–reduction reaction after viewing a single computer animation: the effect of varying the complexity of visual images and depicting water molecules

Abstract

This paper describes two studies comparing students’ explanations of an oxidation–reduction reaction after viewing the chemical demonstration and one of two different particulate-level computer animations. In the first study, the two animations differed primarily in the complexity of the visual images. Students viewing the more simplified animation provided more correct explanations regarding the identity of water and nitrate ions in the animations, the absence of ion pairs, the correct ratios of silver to nitrate ions and silver ions to copper atoms, the electron transfer process, size changes in the atoms and ions as the reaction occurred, the source of blue colour in solution, and the driving force for the reaction. Students viewing the more simplified animation also wrote more correct balanced chemical equations for the reaction compared to students viewing the more complex animation. Students in the first study also noted that the more simplified animation did not depict extraneous information (camera angle changes, the overabundance of water molecules), and did depict relevant information (atom and ion charges, the number of electrons transferred, the source of the blue colour). In the second study, the two animations differed only by whether water molecules were shown or omitted from the animation. Students’ explanations for most concepts were similar for these two groups of students; however, students viewing the animation with water molecules omitted were better able to identify nitrate ions in the animation. The only difference the students in the second study noticed between the two animations is the presence or absence of water molecules, but these student did not agree as to whether showing or omitting water molecules was more beneficial. The results of the two studies together suggest that showing or omitting water molecules in the animations had a limited effect on students’ explanations of the oxidation–reduction process.