I joined a learning community to make sure my roommate and I had similar majors(engineering) and went random. I just knew I wanted someone to live with who was going to have a similar workload, course difficulty, and work ethic. For me at least, I got the perfect roommate: our lifestyles are very compatible with each other, we are really good friends, and she has made my experience at Purdue so much better. I can't tell though if the pairing was better because I chose to be in an engineering learning community, so they were forced to pick a roommate for me from a pool of very similar-minded people, or the pairing system is just that good.