First round only confirmed skills and experience. In the second and third round it was mostly questions about work behavior (e.g. have you ever had a conflict with a co-worker and how did you handle it?) and your interest in the job (e.g. why do you want to work at GP? why do you want to work on this campaign?). Also asked one or two hypothetical questions that were relevant to the job and campaign (e.g. how would you determine the relationship between these two variables) but these were vague and not meant to be technical or tricky.