Slightly off the post but someone mentioned the use of the tests in other industries.
To a large extent, the same apptitude tests are used in the selection processes of a wide variety of industries.
I feely admit that I was very sceptical about their validity when we started using them, but they are a pretty good indicator of who will succeed and who will not, (the quality of instruction and success rate at CATC is entirely down to CATC Management).
Having discussed their usefullness with friends in other industries, they were initially of the same opinion, but rapidly changed their minds when the results spoke for themselves in terms of the quality of candidates they are now recruiting, not to mention the money they save in training costs.
(No, I don't work in NATS or management).