Peer learning for large size Physics lectures in higher education: yes, we can

The academic course on Mechanics and Electromagnetism “Fisica Sperimentale A+B” at Politecnico di Milano was selected to investigate peer learning effects in large size lectures. It was attended by both freshmen attending the first year of Chemical Engineering and those studying Materials and Nanotechnology Engineering during the first term of the academic year 2017-2018. After arranging the students in three different sections on the basis of an alphabetical order, the research team modified the design and pedagogical method of one of these sections. In addition to traditional lectures, the students of this section took periodical tests based on multiple choice quizzes whose provision was implemented by using the on-line portal Socrative and by allowing the students to use their own electronic devices. Immediately after each quiz and without getting any feedback on the accuracy, freshmen would discuss the quizzes in small groups for few minutes. At the end of this debate, they retook the same test. Thanks to the significant bulk of data collected, the findings are likely to show that the average score achieved by the students in the same test, normalised so that the highest value is equal to 10, increases considerably as a consequence of peer discussion: from 5.1 to 6.7 in Mechanics, corresponding to a growth by 32%, and from 3.6 to 5.6 in Electromagnetism, corresponding to an increase by 55%. Moreover, a sensible decrease in the incorrect answers rate emerges in relation to each quiz: on average, 43% and 30% in Mechanics and Electromagnetism respectively. Furthermore, significant and comparable reductions of this rate occur as regards quizzes characterised by both low and high percentage of incorrect answers in quizzes which precede peer learning and peer evaluation. Finally, the percent decrease in incorrect answers given by female students is higher than the male percent reduction in 90% of the Mechanics quizzes and lower in the remaining 10%; conversely, they are both equal to 50% with relation to Electromagnetism quizzes.