Mine was a multi-tiered interview process that is in line with a previous reviewer's report. Initial phone screen with HR, followed by 2 back to back 30-minute interviews with current Research Associates. A case study was next--it was engaging, interesting work & I was very happy doing it--then a 30 minute review over the phone with a Research Manager. In person interviews were next: 5 back to back, including one over breakfast & one over the phone with a Senior VP in NYC. I believe this is typically the end of the line & a decision is made after this step. In my situation I was called back in for 2 more in-person interviews, one of which was with the Senior VP I'd previously spoken to over the phone, as this VP was in town that week.
Everyone who interviewed me asked essentially behavioral questions. Some interviews (breakfast in particular) seemed to be more focused on cultural & personality fit than anything else. The office is arranged with low cubicles, & although people work quietly there seems to be quite a bit of interaction; I think they want to be sure all who work in the office are going to be able to get along with & cooperate with co-workers. They want to be certain you have the ability to ask thoughtful, intelligent questions. Because the job involves asking questions to develop a good council of experts for the client, you have to be able to get at the answers you want even when the client is vague about their needs, or has only an abstract plan at the time they contact you. Research experience, whether as an RA or from doing independent research during university studies, would be very helpful. There seems to be an emphasis on sales as well, as one of the Managers frequently referred to the ability to persuade clients to upgrade their services as being a beneficial skill.
You must be willing & able to accept feedback--much was given, both from interviewers & also from the HR rep, who kept in close contact & was a very professional guiding hand along the way. If you are unclear re: the feedback given, do not hesitate to ask for clarification. I believe inquisitiveness & a genuine desire to improve yourself is held in high esteem here.
Overall I thoroughly enjoyed the interview process. Like the previous reviewer, I also spent dozens of hours preparing. I was happy doing the work & learning more about the company, more so after I met & spent some time with the people who worked there & got a better idea of what their day-to-day was like. I was very disappointed when at the end of this very lengthy & involved process, I was not offered a position.
A financial services background would serve you well, as the lack of this experience was what ended up being detrimental to me, despite performing very well in all interviews & receiving rave reviews at all steps.
(I have left this detailed account because I appreciated those who had previously done the same--they helped me tremendously. I hope this helps you as well.)