In the scenario I had, we had to select one candidate out of four for a secondment role from a store manager role to a project role. Unfortunately its not something you can prep for and its not even dependant on the conclusions you draw really, it seemed to me that they were testing our skills of persuasion and communication, as well as our ability to inclusively debate with other people. As long as you had a clear and articulate explanation that made logical sense they will have been happy. The recruiter disagreed with our conclusion, however i suspect she does this to challenge the potential graduates and see how they react under stern examination. At the assessment there were 4 candidates and two HR representatives, one junior member and one the head of the graduate recruitment scheme.