Initial interview was on-campus with one Nielsen employee from NYC with a required analytical assessment. The assessment is consistent with the other example problems posted here and was very simple SAT-I-level stuff. I received a follow-up about one or two weeks later with a request to set up a an on-site interview a week or two after the call. The on-site interview comprised interviews with three people. After another week of downtime I received an invitation to come in again for another set of interviews (three, again). The culture seems very laid back from my impression of the employees in the interview. They are very nice and genuinely enjoy what they do. I declined the second on-site interview because my impression from the long downtimes between interviews was that the company might be a little too bureaucratic for my desires, and I was growing wearisome of the interview process. Clearly they want the candidate to be a strong fit but I think two three-round onsites after the initial on-campus is a little too much for me personally. Overall the people are very nice but the interview process is far too long. I was unimpressed since I was aiming for a January 2012 start date.