Full on, day long Assessment Centre for a group of 6-8. We had to do a technical exam paper (general engineering knowledge - first year of uni stuff) a reading comprehension test (read a load of documents about a problem and then write an email suggesting a way to fix the problem). We then had a 'proper interview' where the employer looked through your exam paper answers and asked you to explain your answers. They didn't mind if they were incorrect, they just wanted to see how you came across the answer. Finally we had a group exercise looking at the best way to develop a small island. It was an exhausting day! I imagine it's fairly standard for a lot of grad schemes in big companies.