Design and Development of a Learning Progression about Stellar Structure and Evolution

[This paper is part of the Focused Collection on Astronomy Education Research.] In this paper we discuss the design and development of a learning progression (LP) to describe and interpret students' understanding about stellar structure and evolution (SSE). The LP is built upon three content dimensions: hydrostatic equilibrium; composition and aggregation state; functioning and evolution. The data to build up the levels of the hypothetical LP (LP1) came from a 45-minute, seven-question interview, with 33 high school students previously taught about the topic. The questions were adapted from an existing multiple-choice instrument. Data were analyzed using Minstrell's "facets" approach. To assess the validity of LP1, we designed a twelve-hour teaching module featuring paper-and-pencil tasks and practical activities to estimate the stellar structure and evolution parameters. Twenty high school students were interviewed before and after the activities using the same interview protocol. Results informed a revision of LP1 (LP2) and, in parallel, of the module. The revised module included supplementary activities corresponding to changes made to LP1. We then assessed LP2 with 30 high school students through the same interview, submitted before and after the teaching intervention. A final version of the LP (LP3) was then developed drawing on students' emerging reasoning strategies. This paper contributes to research in science education by providing an example of the iterative development of the instruction required to support the student thinking that LPs' levels describe. Concerning astronomy education research, our findings can inform suitable instructional activities more responsive to students' reasoning strategies about stellar structure and evolution

Developing the use of visual representations to explain basic astronomy phenomena

Several decades of research have contributed to our understanding of students’ reasoning about astronomical phenomena. Some authors have pointed out the difficulty in reading and interpreting images used in school textbooks as factors that may justify the persistence of misconceptions. However, only a few studies have investigated to what extent usual textbook images influence students’ understanding of such phenomena. This study examines this issue exploring 13-14 years old students’ explanations, drawings and conceptions about three familiar phenomena: change of seasons, Moon phases and solar/lunar eclipses. The research questions that guided the study were: RQ1) How are students’ explanations and visual representations about familiar astronomical phenomena affected by different imagesupport conditions? RQ2) How are students’ conceptions about familiar astronomical phenomena affected by different image-support conditions? RQ3) Which features of the used images most affected the students’ visual representations and explanations of familiar astronomical phenomena? To answer our research questions, we designed three instructional contexts under increasing support conditions: textbook images and text; teaching booklets with specially designed images and text; only text. To analyze students’ drawings, we used exploratory factor analysis to deconstruct drawings into their most salient elements. To analyze students’ explanations, we adopted a constant comparison method identifying different levels of increasing knowledge. To investigate students’ conceptions, we used a mixed multiple choice/true false baseline questionnaire. For RQ1, results show that the specially designed images condition was effective in helping students producing informed drawings in comparison to text-only condition for all phenomena, and more effective than textbook images condition when one considers seasonal change drawings. Concerning RQ2, the specially designed images condition was the most effective for all phenomena. Concerning RQ3, prevalent elements of astronomy images that affected students’ explanations and visual representations were: elliptical Earth's orbit, position of the Sun with respect to the Moon orbit, Sun, Moon and Earth alignment. Our findings confirm concerns about textbook astronomy images, whose features may interfere with the identification of the relevant factors underlying the phenomena. Moreover, findings of this study suggest that affordances of the specially designed images may play an essential role in scaffolding meaningful understanding of the targeted phenomena. Implications for teaching through and learning from visual representations in astronomy education are briefly discussed

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

Effects of emergency remote instruction during the COVID-19 pandemic on university physics students in Italy

We surveyed a convenience sample of 362 Italian university physics students, asking them to retrospectively assess their experience of emergency remote instruction due to the COVID-19 outbreak. We looked at their psychological well being, motivation for physics, academic orientation, attitude towards physics and physicists, and tried to link these factors to their overall perception of the online instruction. Our results show a general appreciation for the organization and effectiveness of online courses. However, online teaching negatively impacted on engagement and interaction between peers and with the instructors. Only 22% of students in our sample complained of the psychological distress due to remote instruction. Nonetheless, we found a significant decrease in motivational dimensions, such as interest and recognition. Emergency remote instruction also challenged the students’ self-regulation, self-efficacy, and engagement. Finally, the uncertainty about the future resulted in a more pessimistic attitude towards physics, academic performance, and job perspectives

Quantitative experiments to explain the change of seasons

The science education literature shows that students have difficulty understanding what causes the seasons. Incorrect explanations are often due to a lack of knowledge about the physical mechanisms underlying this phenomenon. To address this, we present a module in which the students engage in quantitative measurements with a photovoltaic panel to explain changes to the sunray flow on Earth’s surface over the year. The activities also provide examples of energy transfers between the incoming radiation and the environment to introduce basic features of Earth’s climate. The module was evaluated with 45 secondary school students (aged 17–18) and a pre-/posttest research design. Analysis of students’ learning outcomes supports the effectiveness of the proposed activities

Dal diapason al Sole: una proposta innovativa per l'insegnamento delle onde meccaniche

In questo lavoro presentiamo un modulo innovativo che ha lo scopo di affrontare le piu comuni misconcezioni degli studenti riguardo le onde meccaniche, attraverso la fusione di un contesto tradizionale quale lo studio del suono di un diapason con uno insolito quale lo studio del suono prodotto dal Sole. Gli studenti, utilizzando un software audio digitale, determinano la frequenza fondamentale di un diapason e quindi la frequenza fondamentale delle oscillazioni del Sole. Inoltre viene mostrato come in Fisica si possa utilizzare la stessa tecnica (analisi spettrale) per ottenere informazioni riguardo fenomeni fisici molto diversi. Il modulo e stato proposto in via sperimentale nell'anno scolastico 2014-2015 durante il Piano Lauree Scientiche - Fisica presso l'Universitàa di Napoli a circa 40 studenti frequentanti la classe quarta di Liceo Scientico. Questa sperimentazione sarà il punto di partenza per la realizzazione di uno strumento di valutazione finalizzato ad indagare l'efficacia delle attivitàa presenti nel modulo

Teaching about mechanical waves and sound with a tuning fork and the Sun

Literature in Physics Education has shown that students encounter many difficulties in understanding wave propagation. Such difficulties lead to misconceptions also in understanding sound, often used as context to teach wave propagation. To address these issues, we present in this paper a module in which the students are engaged in computer-based activities dealing with sounds produced by a tuning fork and the Sun. The main reason underlying such choice is to show how the same measurement technique (spectral analysis) can be used to obtain information about very different phenomena. The activities build on a formal analogy to determine the fundamental frequency of sounds emitted by the two sources (tuning fork and Sun). Using a digital audio editor, the sounds are analyzed using three types of graphs: intensity versus time (waveform), intensity versus frequency (spectrum), and frequency versus time (spectrogram). The aim of the activities is to address students' alternative conceptions about the frequency and propagation of mechanical waves using a multi-representation of the same phenomenon. Examples of frequency measurements for the analyzed sounds are reported, as well as paper-and-pencil tasks to determine velocity of sound in the two phenomena. Implications for the teaching of waves and sound are finally discussed

A teaching module about stellar structure and evolution

In this paper, we present a teaching module about stellar structure, functioning and evolution. Drawing from literature in astronomy education, we designed the activities around three key ideas: spectral analysis, mechanical and thermal equilibrium, energy and nuclear reactions. The module is divided into four phases, in which the key ideas for describing stars' functioning and physical mechanisms are gradually introduced. The activities (20 hours) build on previously learned laws in mechanics, thermodynamics, and electromagnetism and help students combine them meaningfully in order to get a complete picture of processes that happens in stars. The module was piloted with two intact classes of secondary school students (N = 59 students, 17–18 years old), using a ten-question multiple-choice questionnaire as research instrument. Results support the effectiveness of the proposed activities. Implications for the teaching of advanced physics topics using stars as fruitful context are briefly discussed