# "The real value of a course is the sharing of intuition"

At 6 a.m. on Saturday mornings, in the quiet of the day, Testerman likes to arise and work on mathematics problems. “You need a calm setting to do math, because you have to be very focused.” Being a good mathematician, this professor, who teaches at EPFL’s School of Basic Sciences, is disciplined even though she can occasionally digress. “In class, I’ll sometimes go off-topic, because I can’t resist a good story.”

This is not surprising for someone who wanted to study literature, art history and theater, before her engineer father convinced her to switch to math. “He told me, ‘An education is expensive, you need to learn something that you can do later on,’ and so I completed a Bachelor’s degree in math and theater.” A double major like this was possible in Virginia, where she grew up – after all, mathematics is a sort of art form. “Sometimes I tell my students, ‘Look at this theorem, isn't it beautiful? It deserves a round of applause.’”

Testerman, who studies the theory of algebraic groups, has always had a passion for math; she loves exploring its intricacies and sharing her knowledge with others. Although she claims that her teaching method – which involves just a blackboard and a piece of chalk – is “very traditional,” her engagement with her students is outstanding. This sense of involvement, along with the fact that she created a MOOC in linear algebra in 2015 and the quality of her teaching in general, have earned her this year’s Credit Suisse Award for Best Teaching.

## To do mathematics

“You can teach a course like a book, but that was never my style. Books don’t tell you how to arrive at an idea. The real value of a course is the sharing of intuition.” Since 2004, Testerman has taught linear and Lie algebras to EPFL Bachelor’s and Master’s students, with the same level of enthusiasm that she has for helping students understand. Her experience and drive made her the ideal person to design a MOOC version of the linear algebra course she teaches to future first-year engineers. But the online course, which consists of some 100 videos, each 10-15 minutes long, covers even more ground. Available on the edX learning platform, it has already been taken by tens of thousands of students from around the world. At EPFL, other professors also use it for their courses, including Simone Deparis who teaches linear algebra using a flipped classroom format. “Developing the course was painstaking and time-consuming,” says Testerman, “but I had the support of a highly skilled team.”

Professor Testerman is not easy-going – her classes are complex and fast-paced. But she’s determined to provide her students with everything they need to pass the course. That’s why she holds office hours where students can drop in and ask questions. “During a one-on-one meeting, I can provide examples that are tailored to their problems and identify areas where I need to improve my teaching.”

Testerman’s goal is to have students solve problems using their own individual approach. For this reason, she gives her first-year students assignments accompanied by detailed solutions, but in later years she provides little or no assistance. "To understand mathematics, you have to do it; students have to follow their own line of reasoning."

Testerman, who earned a PhD from the University of Oregon at the age of 25, knows what it means to “wrestle with problems.” Physics was a big challenge for her during her studies, and her research now requires that she ask herself "a lot of questions.” “I understand what students are going through, and I think that doing research alongside teaching is valuable. Personally, if I don’t do it, I find I get bored.”

## A tremendous challenge

After leaving the US to join her husband in Switzerland, Testerman was offered a position at the University of Warwick in England. “We lived in Geneva and had an au pair for our two children, then aged two and four. I would leave Tuesday morning at 5am and return Friday evening. I estimated that, factoring in time between semesters, I would be able to spend two-thirds of my time at home. I did it for two years, but it was not a long-term solution.”

She stepped down from her position at the University of Warwick, and then spent five years teaching at HES-SO Valais-Wallis before the opportunity arose to join the University of Lausanne and EPFL when the School of Basic Sciences was being set up. “Returning to research after five years was a tremendous challenge.” This Alpine enthusiast, who enjoys a guided mountain run once a year, took up the challenge with gusto. And although research means a great deal to her, training students and looking after their well-being is of equal importance. “It’s essential to create an environment where students interact. I try to remember their first names, even in the large courses, and I ask them for their birthdays. If it coincides with a class day, I give them chocolate and we all sing Happy Birthday.” A short break and a sweet treat, and then it’s back to tackling new math problems.