Effects of instruction on students' overconfidence in introductory quantum mechanics

Students' ability to assess their own knowledge is an important skill in science education. However, students often overestimate their actual performances. In such cases, overconfidence bias arises. Previous studies in physics education have shown that overconfidence bias concerns mainly content areas, such as Newtonian mechanics, where misconceptions are strongly held by students. However, how the received instruction and the levels of understanding of a given topic influence overconfidence bias is yet to be proved. In this paper, we address this issue choosing as content area introductory quantum mechanics (QM). Overall, 408 high school students were involved in the study and randomly assigned to two experimental groups. One group received a textbook-based instruction about introductory QM, whereas the other one received instruction on the same topics through an innovative guided inquiry teaching-learning sequence (TLS), which included also potential pedagogical countermeasures for overconfidence bias. Students of both experimental groups completed a multiple-choice questionnaire and indicated for each item the degree of their confidence in the given answer using a 5-point Likert scale. The overconfidence bias was quantitatively defined and evaluated at person level using a 1D Rasch model. Progress in knowledge about the targeted topics was modeled according to a construct map validated in a previous paper. Results show that, for the whole sample, the overconfidence bias decreased as students progressed along the levels of the construct map. However, findings indicate that students of the TLS group achieved a significantly higher accuracy and a better confidence calibration, while the textbook group exhibited a lower performance and a significantly greater overconfidence bias. Implications for research into overconfidence bias in physics education are briefly discussed

Development of a construct map to describe students' reasoning about introductory quantum mechanics

We present the development and validation of a construct map addressing introductory quantum mechanics topics at the high school level, as a subset of a larger learning progression on quantum mechanics. Topics include energy quantization, photon absorption and emission, the Heisenberg uncertainty principle, atom stability, orbitals, wave function, and electronic properties of materials. To validate the hypothesized construct map, we designed a multiple-choice questionnaire and a 14-h teaching- learning sequence (TLS) designed in strict relation with the levels of the construct map. Twenty-three classes of Italian students (ages 17–18, N 1⁄4 408) were involved in the study: about half (N 1⁄4 200) were exposed to the TLS, while N 1⁄4 208 students received a typical textbook instruction on the same topics targeted by the construct map. Data were analyzed using a 1D Rasch model. Results show that the proposed construct map consistently describes the increasing abilities of students when exposed to instruction. In particular, when exposed to the TLS activities, students more likely move towards the upper levels of the construct map. Findings have implications for instruction designed to support students’ learning in quantum mechanics at the high school level

Design and validation of a two-tier questionnaire on basic aspects in quantum mechanics

We present the design, statistical analysis, and validation of a questionnaire to assess students’ knowledge about basic aspects of quantum mechanics (QM). The QM evaluation (QME) is a true-false and multiple-choice mixed questionnaire that features 10 two-tier items spanning three relevant themes in quantum mechanics: wave behavior of matter, measurement, and atoms and electrons behavior. Its validity was assessed through a pilot administration to students and interviews with course instructors. We checked its internal consistency using both classic test theory and Rasch analysis to account for the different difficulty of each tier and for different scoring methods of the items. The questionnaire was administered to about 450 undergraduate physics students and high school physics teachers. Data show that it is a reliable instrument and all items have a good discriminatory power. Since the test does not require an advanced mathematical knowledge, it ideally lends itself to probe students’ knowledge about quantum mechanics in a variety of university courses, from the introductory ones to those more formal and mathematically oriented

Development and validation of a university students’ progression in learning quantum mechanics through exploratory factor analysis and Rasch analysis

We report an empirical study on the development and validation of a learning progression (LP) in quantum mechanics (QM) at university level. Drawing on research results about students’ reasoning in QM, we designed a hypothetical LP (HLP) consisting of three Big Ideas: Measurement, A toms and Electrons, Wave function. We then developed ten Ordered-Multiple-Choice (OMC) items to assess the construct validity and hierarchy of HLP levels. We administered the questionnaire to 244 students attending the Bachelor in Physics, divided into three groups under different instruction conditions: no course, introductory course, introductory and upper-level course. An additional group of 43 non-physics students, who attended an introductory QM course, was also involved to inspect the role of physics background knowledge . We used exploratory factor analysis and Rasch analysis to analyse collected data. The results provided evidence for the revision of the HLP around only two Big Ideas – Atomic description and measurement; Wave function and its properties in the measurement process – which roughly match the topics covered in the introductory and upper-level courses, respectively. However, the hierarchy of hypothesised levels was substantially confirmed. Implications of our findings for the teaching of QM, and the improvement of the revised LP are also discussed

The dawn of CAMP volcanism and its bearing on the end-Triassic carbon cycle disruption

The cause-and-effect relationship between the ca. 201 Ma eruption of the Central Atlantic magmatic province (CAMP) and the end-Triassic abrupt climate change and mass extinction is at present based on controversial temporal correlations. Upper Triassic sedimentary strata underlying CAMP basalts in Morocco illustrate a clear mineralogical and geochemical fingerprint of early CAMP basaltic eruptions, namely unusually high contents of MgO (10\u201332wt%) and of mafic clay minerals (11\u201384%). In the same rocks a coincident negative carbon-isotope excursion (CIE) is present, equivalent to the so-called \u2018initial negative CIE\u2019 recorded worldwide shortly before the Triassic\u2013Jurassic boundary. The new data show that the onset of CAMP activity preceded the end-Triassic carbon cycle disruption and that the initial negative CIE is unequivocally synchronous with CAMP volcanism. The results of this study strongly support the hypothesis that the culmination of pollution of atmosphere and seawater by CAMP-derived volcanic gases was the proximate cause of the end-Triassic mass extinction

The dawn of CAMP volcanism and its bearing on the end-Triassic carbon cycle disruption

<p>The cause-and-effect relationship between the <em>c</em>. 201 Ma eruption of the Central Atlantic magmatic province (CAMP) and the end-Triassic abrupt climate change and mass extinction is at present based on controversial temporal correlations. Upper Triassic sedimentary strata underlying CAMP basalts in Morocco illustrate a clear mineralogical and geochemical fingerprint of early CAMP basaltic eruptions, namely unusually high contents of MgO (10–32 wt%) and of mafic clay minerals (11–84%). In the same rocks a coincident negative carbon-isotope excursion (CIE) is present, equivalent to the so-called ‘initial negative CIE’ recorded worldwide shortly before the Triassic–Jurassic boundary. The new data show that the onset of CAMP activity preceded the end-Triassic carbon cycle disruption and that the initial negative CIE is unequivocally synchronous with CAMP volcanism. The results of this study strongly support the hypothesis that the culmination of pollution of atmosphere and seawater by CAMP-derived volcanic gases was the proximate cause of the end-Triassic mass extinction. </p