The irony is not lost on Kate Saenko. Now that humans have programmed computers to learn, they want to know exactly what the computers have learned, and how they make decisions after their learning process is complete. To do that, Saenko, a Boston University College of Arts & Sciences associate professor of computer science, used humans--asking them to look at dozens of pictures depicting steps that the computer may have taken on its road to a decision, and identify its most likely path. The humans gave Saenko answers that made sense, but there was a problem: they made sense to humans, and humans, Saenko knew, have biases. In fact, humans don't even understand how they themselves make decisions.