Some individuals seem to intuitively collaborate better in teams, and some teams have repetitively superior results. Cooperative work is a growing need in all workplaces, and it has been thoroughly studied. However, literature has not yet clearly identified its predictors, as it does not present consistent results. Some authors report a reluctance in students to collaborate in teams, whereas others describe its huge advantages. This work intends to explore variables that might influence collaborative learning. We hypothesize that the team size and the scientific field of the students might affect team collaboration and team performance. In this study with Pre- and Post-test, team collaboration was measured using the Team Collaboration Evaluator (TCE) and team performance was assessed by the students’ perceived team effectiveness and by the final project grade given by the instructors. Analysis of a sample of 99 students, from both Computer Science and Psychology bachelor programs, indicates that larger teams show lower team collaboration, but higher team performance. Collected data confirm differences in the evolution of the perceived team collaboration, according to the students’ scientific field. Results are discussed considering the Team Collaboration Evaluator framework.