Abstract:

Nowadays, the pre-university education allows access to undergraduate studies without having studied basic subjects such as Chemistry or Technical Drawing. This fact contributes to have very heterogeneous groups of first year students, with different experience and skills, which hinders the process of teaching and learning. As a consequence, students are discouraged, frustrated and, in some cases, they drop out of higher education. The "classical" approach has the goal of getting all the students to the same level, using the so-called "zero courses", given prior to the start of the lessons. Alternatively, students in heterogeneous groups can work collaboratively, encouraging motivation of the most advantaged students to help their colleagues and pushing low level students to catch up with the average level of the group. This work aims to compare two different strategies, carried out in two different subjects of a first year course in an engineering degree, to deal with heterogeneity in large groups. First, the aforementioned "classical" approach was adapted to an inverted classroom methodology (or flip teaching), to increase motivation and improve practical skills in the chemistry laboratory. The main objective was to improve the understanding of practical procedures and their theoretical foundations by visualizing the development of the laboratory work before the experimental session. To test their understanding, a theoretical-practical questionnaire was mandatory after watching the videos. This methodology is based on the reduction of students’ anxiety caused by their lack of practical laboratory experience, which allows them to concentrate on the theoretical foundations of the experiments. Thus, a leveling of the students is expected before the beginning of the practical sessions that would have to rebound in a better average grade of the whole group. Second, as an "alternative" approach, a collaborative work system was proposed in groups formed by students of heterogeneous level. Self-assessment tests were conducted to have a classification of the students' entry level. The students were allowed to group freely, evaluating their level of heterogeneity a posteriori. During the group work lessons, evaluation data were collected from individual and collective work: in the class room, using standard exercises and Kahoot! tests (motivating through gamification) and out of the classroom, using EdPuzzle and Moodle tools. As main results, in the first experience carried out in the Chemistry course, there was no increase in the average grades compared to previous courses, maintaining the negative trend observed for the last five years. However, in a final survey, the students considered that this methodology was beneficial, they were more motivated and recommended to continue the use of videos for understanding the theoretical and practical concepts before attending the practical lessons. In the second experience, based on a "alternative" approach, students with low initial level obtained better grades when they were in groups with advantaged students. In addition, students with high initial level obtained better grades when they were in heterogeneous groups.

Keywords:

Cooperative, Technical Drawing, Laboratory, Inverted classroom.