Although you apply for a specific role, the interview process is generic and everyone is interviewed together. I was invited to the 'Asda Magic' assessment evening and was with a group of between 10-15 people. Initially everyone is asked to introduce themselves and tell everyone an interesting fact about themselves as a type of 'ice-breaker'. Next you will be split into groups and asked to complete a group task, ours was to compile a list of 10 things you would bring on a spaceship at the end of the world etc etc. It's basically a task to see how you communicate with others and if you are able to listen effectively and work as a team. It's really nothing too heavy! Next you will be interviewed by a manager one-to-one before the evening is concluded. This again isn't too heavy, the questions are generally about customer service.