Mazur credits his family with developing his transformative style. They never hesitated to tackle any questions in childhood, not even awkward ones like “Why am I? or “What is the universe?”

His grandfather, a civil engineer, would give him things to tinker with, and when he was 10 he built his first transistor radio. “You don’t need to be a scientist, we’re all born curious. It’s sort of a sad fact that education beats it out of us.”

After his physics study in Leiden University, he took his father’s advice and went to Harvard to do a postdoc, where he worked with Nobel laureate physics Nicolaas Bloembergen. At Harvard he started a research group that studied the effects of ultrashort laser pulses on different materials and became a professor at Harvard.

When he started teaching physics to pre-medical students nearly four decades ago, he simply imitated his teachers in education via lecture. “For many years I went on thinking that I was a successful educator,” Mazur said. His students did well on their exams and he received high ratings from them in return.

After a number of years, he read an article by physicist David Hestenes that claimed students did not learn anything in their introductory physics course. Hestenes had tested students to see if they understood the concept of “force” and tested their knowledge with real-life examples. They scored badly, as they did not understand the principles behind the formulas. Mazur decided to give his Harvard students the same test, and to his dismay he found out that the majority did poorly.

“Students were able to solve textbook problems and pass exams, but if I asked some very basic word-based questions, they had no clue what I was asking,” he said.

He tried to explain one of the answers to the test, but after 10 minutes his students still looked puzzled. Mazur knew half of the students had given the right answer and in a moment of despair he asked, “Why don’t you discuss it with each other?”

Chaos broke out in class as 250 students discussed the problem with each other, but to his surprise the students who knew the right answer convinced the rest in just two minutes. He realized that the students who had recently learned the material knew where the difficulties were in understanding, whereas he, who had learned it a long time ago, forgot about the difficulties of a beginning learner. This serendipitous discovery changed the way he would teach forever.

He stopped lecturing and started teaching through questioning. He asks his students to read the textbook or his notes before class and in class he asks conceptual, open-ended questions on a relevant topic. After students commit to an answer, Mazur asks them to find a neighbor with a different perspective to convince the other of their answer.

“You see a lot of students as they’re talking have an ‘aha moment,’” Mazur said. “Once you have that aha moment, you know it for life, not just to pass the exam.” He then wraps up with an explanation and the cycle repeats.

Data from these interactive classes demonstrated that this learning method tripled the students’ gains in knowledge. The model also helps to close the knowledge gap between male and female science students in the US and Nordic European countries, where men tend to perform better than women in sciences, Mazur said. “When I lectured that gap just translated up, men gained, women gained, but the gap persisted. With peer instruction, I was able to double the gains, but the women disproportionately gained and the gap was eliminated at the end of the year.”

“Peer Instruction: A User’s Manual,” the book that Mazur published about his learning method, has inspired instructors all over the world. To Mazur’s surprise, Stanford University was one of the first to revise its introductory physics courses to peer instruction, whereas his own Harvard colleagues followed only later.

“It’s kind of ironic. You’re never a prophet in your own backyard,” Mazur said. “Many Dutch universities, such as the University of Groningen and the University of Amsterdam, have been active with this learning method. There’s been a huge transformation in the past 10 years, moving away from passive lecturing to more engaged learning.”