"Keep Calm and Continue Testing." The Harvard student's T-shirt tagline seemed to encapsulate the mood in the frigid room filled with data crunchers. It was just another drizzly Saturday in the MIT neighborhood of Kendall Square in Cambridge, Mass., where mostly young men gazed at their laptops, observing predictive models parsing data representing grocery-store purchases of things like DVDs and milk. It was just another hackathon.
But this time it was sponsored by a consumer-data....