The DARPA contracts will focus on helping machines operate in complex, real-world scenarios. They will also tackle one of the central conundrums in AI: something insiders like to call "explainability." Right now, what motivates the results that algorithms return and the decisions they make is something of a black box. That's worrying enough when it comes to policing posts on a social media site, but it is far scarier when lives are at stake. Military commanders are more likely to trust artificial intelligence if they know what it is "thinking," and the better any of us understands technology, the more responsibly we can use it.