I'm reminded of an ancient Chinese proverb (at least I think it's an ancienct Chinese proverb but I'm really not sure):
in reply to T.I.T.S. Or, Try It To See.
Tell me, I forget;
Show me, I remember;
Involve me, I understand.
I think the "try it and see" approach falls more under the "involve me" idea. Currently I am training a new team member who has no Unix experience and no Perl experience at all. Trying to get him up to speed as quickly as possible. Often I'll watch him stumble over a command and ask me if it's right. I'll look and even if it's wrong, I'll simply ask him to try it and see what happens (if he was going to do something that would cause a major problem, I'd correct the command). Then if the command works, great, if not, see if he can figure out why it did not work. It's working, I think he's getting more to where he can trust himself without having to rely on outside help in getting through things.
Knowing how to do something is fine, but understanding why something worked (or didn't work) is better because when something goes wrong, it makes it easier to back up and figure out why so you can make it work again.