Limitations
MINOR
Some minor concerns have to be taken into account regarding the experiment with real students. The experiment was held during the 2019–2020 academic year, when the pandemic forced all the groups to work through online meetings. We achieved 88% participation, the other 12% were grouped randomly and not considered for the study.In general, the groups consisted of 4 members, but in some classrooms a 5-member group or a 3-member group was required. Moreover, classrooms in different subjects were mainly formed by the same students, but some exceptions had to be considered: some students only attended one subject, and some students were in different classrooms depending on the subject. Nevertheless, around 86% of the students were in the same class in S1 and S2 and our results are based on this sample.We compared our approach with a random grouping and a genetic algorithm in the synthetic experiment, while we could only compare our approach with a random grouping in the real experiment, as is usually done in the literature. In this study we could not include a genetic algorithm in the real experiment, where we would need the same student volunteers in three different subjects, simultaneously, increasing the complexity of the experiment.