Development and Assessment of Self-explaining Skills in College Chemistry Instruction.

摘要

The prevalent trend in chemistry instruction relies on what has been described as the classroom game. In this model, students take a passive role and the instructor does all the explaining (thinking), and learning is trivialized to knowing the correct answers (memorizing) and being able to produce them when prompted (regurgitating). The generation of explanations is central to scientific and technological development. In the process of figuring out explanations, the generation of inferences relies on the application of skills associated with scientific behaviors (e.g., analytical reasoning and critical thinking). The process of explanation generation causes a deeper analysis and revision of the scientific models, thus impacting the conceptual understanding of such models. Although the process of generating authentic explanations is closer to the experience of doing science, this process is seldom replicated in science instruction.;Self-explaining refers to the generation of inferences about causal connections between objects and events. In science, this may be summarized as making sense of how and why actual or hypothetical phenomena take place. Research findings in educational psychology show that implementing activities that elicit self-explaining improves learning in general and specifically enhances authentic learning in the sciences. Research also suggests that self-explaining influences many aspects of cognition, including acquisition of problem-solving skills and conceptual understanding. Although the evidence that links self-explaining and learning is substantial, most of the research has been conducted in experimental settings.;The purpose of this work was to advance knowledge in this area by investigating the effect of different self-explaining tasks on self-explaining behavior and the effect of engaging in different levels of self-explaining on learning chemistry concepts. Unlike most of the research in the field, this work did not focus on advancing procedural knowledge through self-explanation of examples or conceptual understanding through self-explanation of textual information and concepts. Instead, it focused on an experience closer to doing science by presenting a familiar phenomenon to the participants and a fact that would potentially induce cognitive imbalance to then prompt them to self-explain.;This work used a multi-condition, mixed-method approach to categorize students' self-explaining behaviors in response to learning tasks and link it to the performance in a post-learning task. Students were randomly assigned to conditions that included the following: studying an experts' explanation, explaining correct and incorrect answers, explaining agreement with another's answer, and explaining one's own answer for others to use. Data were gathered in the classroom ecology of a university, large-enrollment general chemistry course. Content and construct validity evidence support the functionality of the research instruments for the assessment of conceptual understanding of entropy and the Second Law of Thermodynamics. An in-depth analysis of the post-learning task showed that the data collected from the instrument is reliable, consistent and reproducible.;Findings supported an association between the self-explaining tasks and students' self-explaining behaviors. Results showed distinct categorical self-explaining behaviors in students' written responses. These self-explaining behaviors were associated with the self-explaining task given to the students. Thoughtful design of learning tasks can effectively elicit engagement in sophisticated self-explaining in natural, large-enrollment college chemistry classroom environments. Comparison analyses of performance in the post-learning task suggested that in the context of large-enrollment college chemistry classroom environments, self-explaining activities improved students' conceptual understanding in chemistry.;Overall, the work showed that students can self-explain chemical phenomena and apply the underlying chemistry concepts in the resolution of novel problems without direct intervention of an instructor. This work supports the incorporation of self-explaining activities in the repertoire of teaching practices of both experienced and novice instructors for general chemistry courses.