Interviewing graduates is probably THE most difficult because they know nothing,they have no experience and they dont even know why they went into engineering in the first place so I dont envey you.At least people with a few years under their belts have go some idea of what they are doing.
I was talking to a guy ata university i do some work with and he was saying that post graduate students are required to teach a certain number of hours of graduate courses per week but because there are no electronic postgraduates, or not enough, they end up having to get physics and maths post grads to teach electronics graduate students.