Tracking Mechanistic Reasoning: From Decoding Students’ and Instructors’ Explanations to Developing Mechanistic Explanations for Instruction

Abstract

In Organic Chemistry, students often struggle with mechanistic problem-solving. Instead of using implicit information to explain causal relationships, students often resort to unproductive strategies such as rote memorization or manipulation of representations. The overall goal of the EYE-OC project, in which this PhD project is embedded, is the development of instructional materials that support students in the dealing with reaction mechanisms. While many studies have focused on students’ problem-solving, little is known about the construction of instructional mechanistic explanations and their impact on students’ problem-solving. While frameworks of Chemistry Education Research suggest how mechanistic explanations should be constructed, little is known about how to build them effectively for learners. In this regard, Instructional Research provides general guidance. In addition, little is known about how instructors, e.g., Organic Chemistry professors, construct mechanistic explanations. In this sense, the first study applied the construct of framing. The qualitative content analysis focused on how instructors construct mechanistic explanations as domain experts (expert frame) and how they construct them for instructional contexts (teaching frame). The results show differences between the mechanistic explanations between frames in terms of the elaboration and structure of causal relations (e.g., increase of problem-solving approaches in the teaching frame). The results suggest that instructors are able to adapt their explanations depending on the context, which provides guidance for the design of instructional mechanistic explanations. Theoretical and empirical findings from different research perspectives and the results of the first study were used to develop and implement instructional mechanistic explanations with reasoning steps in tutorial videos. While most of the research on tutorial videos is based on best-practices examples and user evaluation, much is to be learnt about how students process the instructional explanations in tutorial videos. To test the effectiveness of the developed videos, an intervention study with qualitative content analysis was conducted to examine whether students incorporated the reasoning steps into their explanations. It was found that after watching the tutorial videos, students were able to infer more implicit properties and use them in their problem-solving. It was also shown that linking structural to energetic considerations before and after watching the videos is challenging. The findings indicate implementation approaches and ways in which instructional mechanistic explanations can support students in problem-solving. Moreover, they provide a basis for further development of instructional materials. Through the focus on the instruction, the findings of this dissertation extend previous research on mechanistic reasoning, which has primarily focused on students’ (deficient) approaches. Furthermore, the findings of the entire EYE-OC project contribute to an evidence-based exploration of the learning effectiveness of multimedia learning resources, both in terms of visual design and design of the instructional explanation.