162 Chapter 6 Methods During a focus group consisting of three Dutch urologists, one urologist in training, and one cognitive task analysis expert a list of statements was created, describing the surgical steps and possible peri-operative events of the RARP procedure as well as their possible association with (1) direct postoperative complications and (2) functional outcomes. These statements were formulated in order to investigate which steps of the surgery and which peri-operative events should be included in an instrument for video analysis. This assessment instrument will form the basis for further research on the possible associations between surgical skills and adverse postoperative outcomes. Expert panel The expert panel for the Delphi study was selected based on recommendations of three separate independent urologists who are experts in the field of robotic surgery. Based on these recommendations, 18 experts in the field of robot-assisted radical prostatectomy were selected. In this group, multiple proctors and educators of different fellowships in robotic surgery were included since they have intricate knowledge of the possible origins of complications in surgeons with all levels of experience. The experts were invited by e-mail. If no response was given the experts were contacted by telephone to ask whether they were interested to participate in the Delphi study. Consensus procedure To achieve consensus, a two-step procedure was used (figure 1): the first step was an online two-round Delphi Survey involving Dutch urologists experienced in RARP. Fig 1. Visual representation of the Delphi survey.