[This paper is part of the Focused Collection in Investigating and Improving Quantum Education through Research.] The teaching and learning of quantum physics has recently become a topic of increasing interest in physics education research. In particular, the study of two-state systems is gaining importance as a means of teaching quantum physics at various educational levels. Meanwhile, a number of approaches have been developed that are also suitable for high school students. It can be assumed that the different approaches have different degrees of effectiveness in teaching central quantum concepts. However, suitable evaluation instruments to test this are still lacking. Therefore, as a first step, a short questionnaire on quantum measurement, suitable for both research and classroom use, was developed in several steps. First, a questionnaire with open and closed items was created and piloted with a total of N = 120 learners. The responses were evaluated qualitatively using a comprehensive coding manual, which provided insights into learners’ conceptions. These results led to the development of an eight-item questionnaire that could be adapted to different teaching approaches. This questionnaire was subjected to expert review and, finally, successfully tested for its psychometric properties with a sample of N = 201 learners. Overall, our results provide initial empirical evidence that context (i.e., which two-state approach is used) does matter for student learning, but in general, two-state approaches appear to be particularly conducive to learning quantum concepts (specified in this article for quantum measurement) compared to traditional instruction. Published by the American Physical Society 2024

[This paper is part of the Focused Collection in Investigating and Improving Quantum Education through Research.] As one of the successful theories in physics, quantum physics, constructed out of physical ideas and expressed mathematically, provides the required information for the development of technology by describing atomic or quantum systems. For several reasons related to the characteristics of quantum physics knowledge, students struggle with understanding the concepts forcing them to change their classical thinking. However, previous research showed that discussing quantum physics phenomena with peers helped students in problem solving, improving understanding, and constructing quantum physics knowledge. In this study, we focused on students’ knowledge construction in several different quantum physics topics with peer discussions depending on the kind of quantum physics problems and group structure. Examination of students’ tests with 45 quantum physics problems and reflection reports for four sessions during the semester indicated that the occurrence of knowledge construction is associated with group size and gender composition but not with the kind of problems. The knowledge construction condition is also related to group size, and satisfaction with knowledge and disagreements in group discussions are important for the construction of quantum physics knowledge. Published by the American Physical Society 2024