[mrob]

How would you make them answer truthfully? Admitting to being tired either means you're showing personal weakness, or you're calling your superiors incompetent at scheduling. Neither possibility sounds good for your career. I think it would be better to measure reaction times, eg. by making them catch a falling ruler immediately after it's dropped and seeing how far it falls.

[toopok4k3]

This is why good leaders create an environment where you can be honest about such things. You are basically talking about an inhumane system led by fear. Then again we are talking about the navy here...

[cconover]

This is part of the reason why they institute fatigue standards, to try to keep people from being over tired and still working, which led to people being hurt.