The tests are there to prove natural ability so you will be able to keep up during the training, the fact people are practising them for hours on end until they can scrape through them but then struggle during the training (holding everyone else back and making it hard work for the trainers) means the TOCs have had to do eomething to prevent that happening hence the existence of some TOCs requiring more than just a pass.
Trying desperately hard not to derail the thread more than I have already (Apologies Shunter...), but there's a small problem with this 'solution' to people practising too much.
So, you generate an enhanced pass rate for a particular TOC, designed to perhaps weed out people who practiced the tests so much that their eyes bleed, but might not actually be easily trainable...
What happens if those people practice even harder? And scrape through at the enhanced level, with the same trainability problem you give occurring?
It all seems like a 'death spiral' scenario. Aptitude tests come in -> lots of applications -> people practice testing like demons -> TOC's realise and employ enhanced pass rate -> people practice harder -> TOC's then.......?
It simply seems unsustainable to simply employ a higher pass rate as an answer to people doing what people will do...practice and do their best to pass an exam for something that they want to do.
As an aside, this was my first time at sitting any of the assessments. I received the testing companies 'practice material' 2 days before the test. Had to sign a declaration that I was happy to sit the tests as I should have had it 7 days before.
Now, I viewed the practice material as an introduction to what was expected of me. An idea of how the tests would run. The material itself was so different at times to the actual test that I'm not even sure you could call it practice material.
I'm still awaiting my result. I'm pretty happy with how I performed and I didn't practice day and night.
But if what has already been said is true, perhaps I should've done. In designing a higher pass rate, surely you put people who didn't practice to excess at a disadvantage? Leading to people believing that practising is an absolute 'must-do' in order to pass, leading to the very behaviour that you say is not conducive to good trainability.
It's a mad world we live in...I just hope I passed.
*EDIT* - Just went for a ciggie, re-read this and I missed the most important part. I actually agree with the basis of your post (that extreme practice may be employing people who perhaps shouldn't have), but fiddling around with pass rates and whatever doesn't seem like the right solution. Without having any data to fall back on, I would imagine that an awful lot of genuinely trainable people (who pass the industry standard) could be denied employment whilst an awful lot of 'serial-practicing' people still get through. Which tends to discredit the testing as the benchmark of a person capable of learning and give more credence to another artificial recruitment sift.