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Michael Vignal

Publications and source records attributed to Michael Vignal.

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Representational differences in how students compare measurements

Measurement uncertainty plays a critical role in the process of experimental physics. It is useful to be able to assess student proficiency around the topic to iteratively improve instruction and student learning. For the topic of measurement uncertainty, we developed an assessment tool called the Survey of Physics Reasoning on Uncertainty Concepts in Experiments (SPRUCE), which aims to assess students' knowledge, and use of, a variety of concepts related to measurement uncertainty. This assessment includes two isomorphic questions focused on comparing two measurements with uncertainty. One is presented numerically and the other pictorially. Despite the questions probing identical concepts, students answer them in different ways, indicating that they rely on distinct modes of representation to make sense of measurement uncertainty and comparisons. Specifically, students score much higher on the pictorially represented item, which suggests possible instructional changes to leverage students' use of representations while working with concepts of measurement uncertainty.

physics.ed-ph

Overview of couplet scoring in content-focused physics assessments

Content-focused research-based assessment instruments typically use items (i.e., questions) as the unit of assessment for scoring, reporting, and validation. Couplet scoring employs an alternative unit of assessment called a couplet, which is essentially an item viewed and scored through the lens of a specific assessment objective. With couplet scoring, a single item may have more than one assessment objective and therefore more than one couplet and thus more than one score. We outline the components of traditional item scoring, discuss couplet scoring and its benefits, and use both a recently developed content research-based assessment instrument and an existing one to ground our discussion.

physics.ed-ph

Survey of physics reasoning on uncertainty concepts in experiments: an assessment of measurement uncertainty for introductory physics labs

Measurement uncertainty is a critical feature of experimental research in the physical sciences, and the concepts and practices surrounding measurement uncertainty are important components of physics lab courses. However, there has not been a broadly applicable, research-based assessment tool that allows physics instructors to easily measure students' knowledge of measurement uncertainty concepts and practices. To address this need, we employed Evidence-Centered Design to create the Survey of Physics Reasoning on Uncertainty Concepts in Experiments (SPRUCE). SPRUCE is a pre-post assessment instrument intended for use in introductory (first- and second-year) physics lab courses to help instructors and researchers identify student strengths and challenges with measurement uncertainty. In this paper, we discuss the development of SPRUCE's assessment items guided by Evidence-Centered Design, focusing on how instructors' and researchers' assessment priorities were incorporated into the assessment items and how students' reasoning from pilot testing informed decisions around item answer options. We also present an example of some of the feedback an instructor would receive after implementing SPRUCE in a pre-post fashion, along with a brief discussion of how that feedback could be interpreted and acted upon.

physics.ed-ph

Investigating Unprompted and Prompted Diagrams Generated by Physics MajorsDuring Problem Solving

Diagrams are ubiquitous in physics, especially in physics education and physics problem solving. Problem solvers may generate diagrams to orient to a scenario, to organize information, to directly extract an answer, or as a tool of communication. In this study, we interviewed 19 undergraduate and graduate physics majors, asking them to solve 18 multiple-choice physics problems -- with no prompting regarding diagrams -- and then six diagramming tasks of situations similar to six of the multiple-choice problems. By comparing spontaneously generated and prompted diagrams, we identify different diagramming elements and features used by physics majors acting towards different ends (\textit{i.e.,} in different epistemic frames). We found that different physical contexts impact how critical it is to draw an accurate diagram, and that the differences in diagramming between cohorts (\textit{e.g.}, between lower-division undergraduate and graduate students) seem to be smaller than the differences within a cohort. We also explore implications for teaching and research.

physics.ed-ph

Investigating graduate student reasoning on a conceptual entropy questionnaire

Student learning in upper division thermal physics has not been studied to the same extent as in other courses like electromagnetism and quantum mechanics. Studies addressing reasoning and learning at the graduate level are even more limited. In this study, we conducted think-aloud interviews with eight graduate students involving questions centered around a set of entropy related conceptual tasks, two of which are similar to tasks presented to undergraduates in other studies. We discuss patterns in student reasoning on each question then discuss themes that appeared across questions. We identify conceptual resources that students frequently used to reason about the interview tasks and compare them to prior work. We observed graduate students commonly thinking about entropy in relationship to a number of states, even in situations where such a connection was not directly relevant. Graduate students also frequently made direct associations between entropy and temperature, despite there being no general, explicit relationship between the two quantities. On the whole, graduate students demonstrated adaptability and metacognitive awareness in their approach to reasoning about entropy.

physics.ed-ph