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Prior research has shown that physics students often think about experimental procedures and data analysis very differently from experts. One key framework for analyzing student thinking has found that student thinking is more point-like, putting emphasis on the results of a single experimental trial, whereas set-like thinking relies on the results of many trials. Recent work, however, has found that students rarely fall into one of these two extremes, which may be a limitation of how student thinking is evaluated. Measurements of student thinking have focused on probing students’ procedural knowledge by asking them, for example, what steps they might take next in an experiment. Two common refrains are to collect more data, or to improve the experiment and collect better data. In both of these cases, the underlying reasons behind student responses could be based in point-like or set-like thinking. In this study we use individual student interviews to investigate how advanced physics students believe the collection of more and better data will affect the results of a classical and a quantum mechanical experiment. The results inform future frameworks and assessments for characterizing students thinking between the extremes of point and set reasoning in both classical and quantum regimes. 2020 

Measurement uncertainty and experimental error are important concepts taught in undergraduate physics laboratories. Although student ideas about error and uncertainty in introductory classical mechanics lab experiments have been studied extensively, there is relatively limited research on student thinking about experimental measurement uncertainty in quantum mechanics. In this work, we used semi-structured interviews to study advanced physics students’ interpretations of fictitious data distributions from two common undergraduate laboratory experiments in quantum mechanics and one in classical mechanics. To analyze these interpretations, we developed a coding scheme that classifies student responses based on what factors they believe create un- certainty and differentiates between different types of uncertainty (e.g. imprecision, inaccuracy). We found that participants in our study expressed a variety of ideas about measurement uncertainty that varied with the context (classical/quantum) and the type of uncertainty. 

Measurements in quantum mechanics are often taught in an abstract, theoretical context. Compared to what is known about student understanding of experimental data in classical mechanics, it is unclear how students think about measurement and uncertainty in the context of experimental data from quantum mechanical systems. In this paper, we tested how students interpret the variability in data from hypothetical experiments in classical and quantum mechanics. We conducted semi-structured interviews with 20 students who had taken quantum mechanics courses and analyzed to which sources they attribute variability in the data. We found that in the quantum mechanics context, most students interpret any variability in the data as irreducible and inherent to the theory. While acknowledging the influence of experimenter error, limited resolution of measurement equipment, and confounding variables (like air resistance) in classical mechanics, many students did not recognize the influence of such effects in quantum mechanics. Some students expressed the view that there are inherently fewer confounding variables in Quantum Mechanics and the equipment used is more precise. We derive tentative implications for instruction and propose further research to test the influence of framing on the responses to our interview protocol.