Arturo Colantonio

In this study, we analyse high school students’ conceptual understanding of cosmology. Drawing from previous studies in astronomy education and accepted scientific models of the universe, we identified seven dimensions that we deemed as important to understand key concepts of cosmology: (i) age of the Universe and its determination, (ii) Big Bang, (iii) expansion and future evolution, (iv) how temperature and composition change with time, (v) celestial objects and their relationship, (vi) black holes and dark matter, (vii) time and distance scales. Then, we designed a questionnaire featuring nineteen open-ended questions. Content validity was checked with three professional astrophysicists. The questionnaire was administered to 411 high school students (17 to 19-year-old) who had already received curricular instruction about cosmology in Earth Sciences and Physics classes. Students' responses to questions related to dimensions (i-iv) were first categorized using a grounded approach and then combined through cluster analysis to identify common patterns of students’ understanding. Data suggest that: (a) only 15% of students are aware of any experimental evidence to support the Big Bang or the estimate of Universe age; (b) about two-thirds of the students held alternative or non-scientific views about Universe expansion and evolution; (c) about half of the sample had no idea about how Universe temperature changed in time . Findings raise the question of how to foster a sound conceptual understanding of Cosmology. To address this issue, we are developing a teaching-learning sequence focused on the identified dimensions."