Physicist talks of his struggle to understand how students learn
After 38 years of teaching the freshman physics class at the Massachusetts Institute of Technology, professor David Pritchard has reached some profound revelations about education and learning.
Pritchard detailed his findings and what those findings have inspired in a talk hosted by the Physics department last Tuesday. These discoveries about learning pushed him to create MasteringPhysics, an online website designed to help students work through homework problems without a teacher.
Pritchard first investigated study habits, examining those of “6,000 students from all over the world,” according to his talk. They found that in the beginning of the semester, students regularly tried to read the textbook, but after the first midterm the number of pages they read plummeted. Interestingly, when midterms were imminent, that figure would explode for about a week, then drop back down again. Pritchard said, “I showed this graph to a friend of mine who had written a textbook, and he said, ‘Damn it, Dave, I spent seven years perfecting my textbook. I should have just written a handbook!’”
To resolve this problem in his own physics classroom, Pritchard decided to create a model that would predict a student’s performance in the class based on a variety of factors: whether they worked alone, whether they read the textbook regularly, when they started to work on the homework, and other variables. According to Pritchard, the team was surprised to find that the most important success factor was not study habits or office hours attendance, but whether or not students were cheating on the homework.
The team also investigated conceptual questions designed to test qualitative understanding. Qualitative understanding is often tested with word problems like, “If a truck and a motorcycle crash into each other, is the force the motorcycle exerts on the car greater than, equal to, or less than the force the car exerts on the motorcycle?” They concluded that within the group of 6,000 students, the number of conceptual questions answered had virtually no impact on the final exam score — a result that shook Pritchard. Proficiency with analytical, math-based questions tended to lead to better test scores, but thinking about the physical implications of a problem did not.
“There are some wide disparities in what we want to teach and what they want to learn,” Pritchard said. “They want to know about the relationships of this mechanics stuff to their real-world life. And we want to tell them that this is a beautiful subject which all comes from Newton’s laws.”
Reflecting on this disparity between students and teachers, he added, “What we don’t teach them, which we should, is that [physics] is the beginning of modern science, of making mathematical models of the world. We don’t ever tell them that.”
Pritchard concluded by expressing his support for the “flipped classroom” teaching model, where students read the textbook and watch lectures outside of class, then work through problems during class time while professors provide assistance when necessary. After implementing the model in his own classroom, he found great advances in test scores and comprehension.
Even after 38 years, he said, he’s still learning.