Concept Inventories for Electrochemistry and Electrochemical Engineering

Abstract

Conceptual understanding is essential to the development of competence and confidence in a particular field. Mastering concepts also plays a critical role in organizing material for recall and later use. Concept inventories are research-based assessment instruments that probe conceptual understanding. These inventories have been used in physics, thermal sciences, and other fields of science, engineering, and mathematics; however, no application to electrochemical systems was found. Rather than a means of presenting the course content, the concept inventory is used to assess the effectiveness of teaching and to reveal where students are missing key ideas and principles. Although some studies of misunderstandings related to electrochemistry are available, these tend to focus on a few narrow topics, often at the high school or freshman chemistry level, and do not explore more advanced topics, such as current distributions or the effect of mass transfer on cyclic voltammetry. Six concept inventories that cover electrochemical fundamentals (e.g., Faraday’s law), thermodynamics, electro-kinetics, mass transfer, porous electrodes, and electroanalytical techniques were developed and given to students at the Georgia Institute of Technology and Brigham Young University. These consisted primarily of multiple choice questions, with one correct answer and several distractors, which are intended to probe conceptual understanding. Student performance has been compiled and will be discussed in relation to the desired conceptual understanding. As expected, the inventories clearly showed deficiencies in student understanding of important concepts. The presentation includes a discussion of common concepts that prove difficult for students, possible sources of these misunderstandings, and suggestions for changing instructional approaches. In addition, the effectiveness of the questions was also evaluated. This evaluation included determination of a discrimination index for each question, which was calculated automatically by the Canvas learning management system. This metric provides a measure of how well a single question can tell the difference (or discriminate) between students who do well on a test and those who do not. It divides students into groups based on their score on the entire concept inventory and examines the correlation between performance on the specific question and the performance of the group on the complete exam. Second, based on the frequency that a wrong answer was selected, the effectiveness of the distractors was assessed. The distractors are intended to provide instructors with insight into the misunderstandings held by the students. However, if students rarely or never pick a particular incorrect answer, then it is not useful as a distractor and should be eliminated. The concept inventory continues to be developed beyond the first generation reported here. Within Canvas, a “sandbox” has been established that allows educators from different institutions to access these concept inventories. Sets of questions can then be transferred to instructor’s home institution for use with their students. We also look to the community for help in adding new content and refining questions in order to enhance the education of students in this important field.