Meaningful Contrasts - Investigating the Potential of Scaffolded Contrasting Cases to Promote Students’ Mechanistic Reasoning in Organic Chemistry
Organic Molecular Chemistry - Synthesis and Characterisation
Final Report Abstract
Studies in organic chemistry education from the last decades have shown that there is a significant discrepancy between what students should be able to do in Organic Chemistry and the skills they actually demonstrate. Students' surface-level focus when dealing with representations hinders proper interpretation of organic chemical representations and the application of conceptual knowledge. Studies indicate that successful mechanistic reasoning depends on students' ability to link surface features of structures with implicit properties, perceive reactions as processes, and be less product-oriented in problem-solving. In our former studies, we have shown that solving contrasting cases in organic chemistry follows a basic reasoning structure that can be used to scaffold students in solving contrasting cases. Based on this work and in preparation for a larger intervention study, we conducted a pre-post mixed methods study to determine the influence of prior knowledge on students' work with a scaffold as well as if conceptual knowledge increases through scaffolded contrasting cases. Students’ answers in this study were qualitatively analyzed in the dimension of causal complexity and multivariateness, which resulted in five qualitative patterns. We could document, furthermore, that students with lower scores in the conceptual knowledge pretest benefitted more from the scaffold, showing significant learning gains in conceptual knowledge compared to students with higher prior knowledge. A key finding was that higher causal complexity in students’ answers correlated with increased conceptual knowledge, regardless of initial scores in the conceptual knowledge test. However, surprisingly, students using univariate reasoning in the scaffold showed greater improvement than those using multivariate reasoning. Besides these promising findings that students with low prior knowledge seem to profit from scaffolded contrasting cases, empirical evidence was still lacking if the task format itself or the use of a scaffold improves students’ ability to think mechanistically. To address this research gap, we investigated in a pre-post intervention study the effects of 1.) different task formats in comparing single cases to contrasting cases and 2.) scaffolded contrasting cases compared to a non-scaffolded setting on students' conceptual understanding and their expressed causality. Thus, the main study of this project analyzed the effect of task format and scaffolding on students' learning gains in organic chemistry and compared the effectiveness of scaffolded contrasting cases, non-scaffolded contrasting cases, and single cases in enhancing students' learning gains. The results show that scaffolding is particularly beneficial for students with low prior knowledge and is most effective when tasks require mechanistic reasoning. However, contrasting cases without scaffolding also positively impact learning, indicating a potential contribution of high cognitive load for the scaffolded group. Overall, this project revealed the complex interplay of prior knowledge, task format, as well as guidance on students’ learning gains. Surprisingly, the results were not as clear as expected, and measures of perceived difficulty and cognitive load indicate that multiple factors might promote or hinder the usage of scaffolds and contrasting cases that have not yet been covered in this study. More adaptive and individual scaffolds, supported by technology, might better address the individual needs of students.
Publications
-
Should we scaffold it? – Analysing students’ learning gains to evaluate the effect of task format and scaffolding, Int. J. Sci. Educ., under review.
Kranz, D., Martin, P. P., Schween, M. & Graulich, N.
-
Mechanistisches Denken anleiten - geht das?, In: Habig, S. (Hrsg.), Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch?, Gesellschaft für Didaktik der Chemie und Physik, Digitale Jahrestagung 2020, S. 212-215.
Kranz, D. & Graulich, N.
-
Investigating students’ reasoning over time for case comparisons of acyl transfer reaction mechanisms. Chemistry Education Research and Practice, 22(2), 364-381.
Watts, Field M.; Zaimi, Ina; Kranz, David; Graulich, Nicole & Shultz, Ginger V.
-
Patterns of reasoning – exploring the interplay of students’ work with a scaffold and their conceptual knowledge in organic chemistry. Chemistry Education Research and Practice, 24(2), 453-477.
Kranz, David; Schween, Michael & Graulich, Nicole
-
Revealing Rubric Relations: Investigating the Interdependence of a Research-Informed and a Machine Learning-Based Rubric in Assessing Student Reasoning in Chemistry. International Journal of Artificial Intelligence in Education, 35(3), 1465-1503.
Martin, Paul P.; Kranz, David & Graulich, Nicole
-
Why comparing matters – on case comparisons in organic chemistry. Frontiers in Education, 9.
Graulich, Nicole & Lieber, Leonie
-
“That's not a super important point”: second-semester organic chemistry students’ lines of reasoning when comparing substitution reactions. Chemistry Education Research and Practice, 26(1), 112-125.
Zaimi, Ina; Watts, Field M.; Kranz, David; Graulich, Nicole & Shultz, Ginger V.
