Algorithms can embed bias, they can propagate or even exacerbate inequality, or they can just be plain inaccurate. How do we keep track of all the potential problems? How do we make sure the algorithms we build “work well”? What do we even mean by that? In this talk Cathy O’Neil will introduce the ethical matrix, a construction borrowed from moral philosophy, as a way of organizing our thoughts around important and urgent questions like these.