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# Between Yes and No: making decisions under uncertainty (Prof. Ami Radunskaya)

## September 28 @ 4:15 pm - 5:30 pm

**Title: **Between Yes and No: making decisions under uncertainty.

**Speaker:** Ami Radunskaya, Department of Mathematics and Statistics, Pomona College

**Abstract:** Often we attempt to answer a question with a “yes” or a “no” by developing predictive models (“Will the small remaining population of axolotls survive outside of their native wetlands?”) or by implementing binary classifiers (“Is this a cat or a dog?”). However, the answers that are provided by our models are often given in terms of probabilities. Even more confusing, different models – equally good according to accuracy metrics – can produce conflicting answers.

In this talk, I will explore these issues and discuss their implications. How do we interpret an answer that is neither “yes” nor “no”? For example, a PCR test for COVID yields a probability. How does the choice of threshold affect the individual? How does it affect policy decisions or the course of the disease? How can we disentangle the predictions given by competing models, i.e. how can we deal with predictive multiplicity? For example, if two models disagree on whether or not someone is a loan risk, which one should be trusted? Which groups are most affected? What new metrics can be used to compare models?

A California native, Professor Radunskaya received her Ph.D. in Mathematics from Stanford University. She has been a faculty member in the Math Department at Pomona College since 1994. In her research, she specializes in ergodic theory, dynamical systems, and applications to various “real-world” problems. Some current research projects involve mathematical models of cancer immunotherapy, developing strategies for targeted drug delivery to the brain, and studying stochastic perturbations of dynamical systems.

Professor Radunskaya believes strongly in the power of collaboration and that everyone can learn to enjoy mathematics; as President of the Association of Women in Mathematics, she encouraged collaborative research, international outreach, and cooperation between all the mathematical societies. She is the President of the EDGE (Enhancing Diversity in Graduate Education) Foundation, whose summer program won a “Mathematics Program that Makes a Difference” award from the American Mathematics Society in 2007, and a Presidential Award for Excellence in Science, Mathematics and Engineering Mentoring (PAESMEM) in 2017.

Professor Radunskaya was recently elected as a Fellow of the Association for Women in Mathematics and the American Mathematical Society, and she is the recipient of several awards, including a WIG teaching award in 2012 and the 2017 AAAS Mentor-of-the-year award. She was featured in the documentary “The Empowerment Project: ordinary women doing extraordinary things”, as well as in the recent book by Talithia Williams: “Power in Numbers: the Rebel Women of Mathematics”.