Untersuchung zur Fähigkeit des konzeptuellen Kategorisierens mit Hilfe von Sortierungsaufgaben (CESTs)
Zusammenfassung der Projektergebnisse
Organic chemistry ranks among the hardest subjects for college students; not only because of the large amount of factual knowledge, but also because reasoning in organic chemistry is mainly driven by a multi-conceptual way of thinking. The description of a molecular transformation or the reactivity of a compound involves the application of different chemical concepts, principles, theories and various conditional variables. One key competence for successful problem solving in organic chemistry is the ability to identify and classify important reactions or mechanistic steps for clearly defining a given problem. Despite the extensive research in problem solving, we still do not know enough about students' reasoning with chemical concepts. The CESTs (concept-eliciting sorting tasks) project addresses this need by using concept-eliciting sorting tasks in a qualitative interview study in order to characterize the conceptual categorization ability of undergraduate students. For our purpose, we designed various categorization tasks, to investigate the critical attribute a student uses to categorize a selection of organic reactions. Previous research results suggested that students generally rely on surface features while reasoning with static molecules. This project broadens the current perspective and focuses on students' perspective on organic reactions. Initially the project was designed for carbonyl reactions. However we decided to use alkene addition reactions, as the similarity on the surface level and differences on the mechanistic level are higher in this reaction family. Twelve undergraduate students were recruited from a large introductory organic chemistry class for science majors. The interviews were analyzed using an adapted model from Gentner and Markman (1997). The choices and categories made during the exercises were coded based on the degree of surface and deep-level attributes used for the categorization. The analysis revealed that the students' choice of surface-related attributes during the categorization task, especially the focus on change of functionality was dominant, whereas the use of mechanistic information was scattered and inaccurate. Students develop a strong reliance on perceptual attributes, rather than the ability to embed the more important mechanistic information. The information processing behavior observed in this study showed that students are using effective strategies to interpret the surface-level of organic reactions and as such respond to the dominant focus on functionality or structural change conveyed in a traditional organic chemistry classroom. At first glance their categorization behavior resembles an expert behavior in chemistry, but students discard the chemical knowledge behind the presented reactions. While they are able to easily recognize a learned reaction, they struggle to derive possible mechanistic implications in unfamiliar cases and resort to a matching strategy, i.e. distributing atoms of the reagent onto the substrate of the starting material. The causal mechanistic relations that an expert chemist would use to interpret an organic reaction are missing in the students' reasoning process. Future work is dedicated to determine how students' causal reasoning in organic chemistry develops over the course of their study and to outline possible strategies to foster mechanistic reasoning.
Projektbezogene Publikationen (Auswahl)
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"Categorization tasks to elucidate the conceptual understanding of students in organic chemistry", Poster presented at the Gordon Research conference on chemistry Education, Salve-Regina University, Newport, RI, 01.06-06.06.2014
Graulich, Nicole
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Intuitive Judgments Govern Students' Answering Patterns in Multiple-Choice Exercises in Organic Chemistry, J. Chem. Ed., 2014, Article ASAP
Graulich, Nicole
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The Tip of the Iceberg in Organic Chemistry Classes: How do Students Deal with the Invisible, Chem. Educ. Res. Pract., 2014, Advanced Articles
Graulich, Nicole
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Investigating students' similarity judgments in organic chemistry. Chem. Educ. Res. Pract., 2017, 18, 774-784
Graulich, Nicole, Bhattacharyya, Gautam
