Formative feedback using pseudo peer diagrams: Evaluating system equilibrium of buoyancy forces.

摘要

This study introduces an innovative instructional method, called "pseudo peer diagram" (PPD), where students employ executive skills to compare and contrast their work with others' as a formative feedback mechanism. The focus of this study is how students compare and contrast their own diagrams with the pseudo peer diagrams as a stimulus to evaluate their own work. This is in contrast to alternative methods of learning by example which focus on how students interpret a diagram to make sense of a context. How students engage in the task of making sense of the content can provide instructors with a powerful pedagogical approach to support active learning. The learning context to examine this formative assessment strategy is a series of in-depth questions related to buoyancy forces as a system in equilibrium. Fourteen second and third year undergraduate engineering students were asked to generate free body diagrams to interpret equilibrium in the provided systems. Then PPDs were presented as a feedback mechanism to engage students in metacogitive reflection. To understand how individuals cognitively process PPDs, this study used think-aloud protocol to make students' cognition explicit. This study revealed several challenges that students encountered when they used free body diagrams to interpret system equilibrium. First, students' abilities to interpret systems or system equilibrium were greatly associated with the complexity of the tasks. They could easily comprehend and reason with classic scenarios that were frequently learned from textbooks commonly associated with basic physics, but when encountering new tasks that require the analysis of complex structures often found in engineering contexts, they were not able to perform as well. Most of them relied on shallow representations to illustrate superficial features of the tasks. And they usually neglected differentiating the finer details of the situations. Three participants requested step-by-step guidance from the experts to understand the experts' reasoning process. In addition, several students indicated their unwillingness to decompose the system and operate on the sub-systems. This study also indicated the effectiveness of PPDs in externalizing students' understanding of system equilibrium. Many students mentioned that PPDs confirmed their initial thinking, helped them notice errors and missing features, and better comprehended the contexts and scenarios. In addition, the nature of the PPDs provided multiple perspectives, from both the novice and the expert, to students. The result of this low-cost, paper-and-pencil version study has the potential to inform researchers of the rationale and guidelines to build future automatic feedback systems within the scope of first-year engineering education. This research is also relevant to engineering instructors and researchers who want to develop students' abilities to use cognitive strategies effectively. It may also interest engineering instructors who are willing to apply new instructional methods and tools to facilitate students to overcome complex design challenges.