# Interview with Bernhard Klingenberg

By Nam Nguyen ’19

Klingenberg (right) tells Nguyen about his recently published textbook, “Statistics: The Art and Science of Learning from Data.”

When did you discover your passion for mathematics?

I was really bad at math in middle school. In 11th grade, all of a sudden, I understood what the textbook said. The best moment was when my teacher got stuck when trying to find the volume of a body generated by revolving a graph about the x-axis. Meanwhile, I knew exactly how to do it. So I volunteered to solve the problem, to the surprise of my peers. From then on, I knew that I loved math and wanted to study it..

What is your favorite mathematical theorem?

I would say  The Central Limit Theorem. It is really powerful in predicting the behavior of averages or “means.” Basically the theorem states that the arithmetic mean of a large number of independent variables will always be normally distributed, regardless of the distribution these variables came from.

What are you currently researching?

My research focuses on exact confidence intervals. This concept is applied when you have two success counts and try to look for a parameter called the difference in success proportions. For instance, let’s assume that you want to compare a drug to a placebo in a clinical trial. To say which treatment works better, you need to look at the success probability of both. Using an exact confidence interval allows us to compare success probabilities of the two treatments and come to a conclusion. The advantage of the exact approach is that it provides guaranteed 95% confidence in the interval without the need for a large amount of data.

What is your plan for the near future?

I am trying to finish my research and publish the result. Besides that, I’m designing a web-interface program that utilizes and presents my research to find confidence intervals without heavy computation. Additionally, I’m putting finishing touches on a textbook on introductory statistics. I also plan to have a publication on medical statistics, a field that I have been working in for a long time.

Why did you choose University of Florida for your PhD research?

It was quite difficult for me to continue my research on statistics in Austria because post-graduate study there focuses more on theoretical side of mathematics. Therefore, I decided to seek my PhD in the US. My last year at graduate school in Austria, I studied a book on categorical data analysis and was especially intrigued by an analysis of alligators’ food choices. Subsequently, I ended up with a Fulbright scholarship at the University of Florida to do research with the author of the book and to meet all the alligators there.

Do you have any hobbies?

Definitely! One of them is scuba diving because I like to explore space and the underwater world in 3D. I also love to swim and play a few sports such as basketball and tennis. Besides all of that, I also spend a significant amount of my free time on photography.

What do you think of a liberal arts college like Williams?

I actually did not know anything about liberal arts education and college before coming to Williams. I also had no ideas about residential life in a small college like Williams; I grew up in a town which just had three big universities. However, as I understood more about liberal arts, I considered it a great model of education. During my free time, I often go to dining halls with students or enjoy some sports events. I really love it here and hope to get more attached to this community in the years to come.

Do you have any advice for aspiring statistics majors?

Get involved in as many applied projects as you can. Get familiar with data analysis and statistical modelling. Hands-on experience is necessary to advance in statistics. It gives you ideas of what classes to take or what research to pursue.