One Thursday afternoon in 2015, I got a spontaneous notification on my phone telling me how long it would take to drive to my favourite restaurant under current traffic conditions. This was alarming, not only because it implied that my phone had figured out what my favourite restaurant was without ever asking explicitly, but also because it suggested that my phone knew enough about my eating habits to realize that I liked to go out to dinner on Thursdays specifically.

As our phones, our laptops and our Amazon Echos collect increasing amounts of data about us — and impute even more — data privacy is becoming a greater and greater concern for research as well as government and industry applications. That’s why I wanted to speak to Harvard PhD student and frequent Towards Data Science contributor Matthew Stewart about to get an introduction to some of the key principles behind data privacy. Matthew is a prolific blogger, and his research work at Harvard is focused on applications of machine learning to environmental sciences, a topic we also discuss during this episode.