Science and engineering for what? A large-scale analysis of theme selection in K-12 science and engineering fair projects

Science and Engineering Fairs (SEFs) play a pivotal role in K-12 education, enabling students to engage in science and engineering practices. Particularly, they allow students to experience authentic and open inquiry processes, by defining which themes, questions and approaches will guide their efforts. This study analyses over 5,000 projects presented at FEBRACE, a national science fair in Brazil, over a span of 20 years, employing topic modelling to identify and examine the predominant themes guiding students' investigations and designs. The findings indicate a diverse range of topics that vary significantly across time, region, and educational settings. We argue these findings illustrate the authentic and open aspects of students' inquiries, highlighting SEFs as spaces for culturally responsive science learning. Furthermore, the methodology employed in this study can serve as a valuable tool for similar analyses in other educational contexts, encouraging further exploration of theme selection and project design in SEFs. Finally, we emphasise the importance of equipping both students and teachers with resources to engage a more diverse range of participants and support the varied interests that students bring to their scientific and engineering endeavours, both within and beyond the context of SEFs.