Once you are identified as a candidate you will be set up to take a phone interview from Gallop that will take 1 to 1.5 hours. This interview is a barrage of questions meant to rate characteristics in order to derive your personality type with the desirable characteristics being a driver type personality. If you don't fit you most likely will never be contacted again.
The one area I disagree with this interview is that the questions are not always in context and the interviewer will not give you additional detail. For example, they are going to ask you how loyal you are on a scale of 1-5. Loyalty is an attribute of an amiable characteristic and giving yourself a high score will not do you good. Being loyal can also give others an influence edge. However, when I responded about loyalty I meant in a sense that I am loyal to the company and making good business decisions and not loyalties based on any individual or other product/company.
If you want to do well then look up driver type characteristics (self confident, organizing, persuasive, forceful, quick to act, risk taking) and don't overrate yourself on people oriented characteristics (trusting, loyal, helpful, understanding, idealistic) or analytical characteristics (analytical, cautious, thorough). This is a little counter intuitive to standard interviewing were most want to make sure you're a fit with others along with the right skill set.