I joined the MIT Media Lab six years ago, as the head of the Center for Civic Media. Nathan Matias was one of my first two students (along with Matt Stempeck, who graduated in 2013) and he stuck around for the PhD. Today Nathan defended his dissertation—on using causal effects experiments to test governance strategies on Reddit—in front of me, Tarleton Gillespie, and Betsy Levy Paluck, a pretty amazing committee.

Nathan is my first doctoral student, and I wanted to do something memorable to commemorate his achievement. I noted that Finnish PhD programs award a top hat and sword to their graduates so that they will be prepared to defend truth, and noted that PhD defenses seemed to be surprisingly light on actual defense...

And so after his presentation and a vigorous Q&A exchange with the audience and the committee, I presented Nathan with a sword signed by the three committee members...then drew my own sword from its hidden sheath and challenged him to defeat me in single combat to earn his doctorate.

I am pleased to report that he succeeded, and that we now have a new Center for Civic Media tradition: when you receive your degree, you receive a sword signed by your committee, and you sign the sword I will use to graduate future PhD students.

I couldn't have asked for a better first PhD student than Nathan, who's taught me far more than I've taught him and made me look good in the process. And as he celebrates with his family, I am quietly celebrating the wonderful milestone of being able to bring such an amazing student into the academy, an institution that has bent every possible rule to accommodate my unusual path. Congratulations, Nathan, and thanks to you, your colleagues at Civic, Betsy, Tarleton, and the MIT Media Lab.