If it were me, I'd look at which departments the superstars you want to be studying under are in. At Columbia, Jebara is in CS and has an opening (http://www.cs

If it were me, I'd look at which departments the superstars you want to be studying under are in. At Columbia, Jebara is in CS and has an opening (http://www.cs.columbia.edu/~jebara/prospective.html http://www.cs.columbia.edu/~jebara/prospective.html). Also, it kind of depends where your interests lie. If you want to use big data to create intelligent machines, or you're interested in the logistics of working with massive datasets, maybe CS. If you want to use big data for hypothesis testing, or you're more interested in theory related to math modeling, maybe stats. Good luck!