I've been busy for most of this thread, but part of what I do is test prospective employees, and employees moving up in pay level.
My thoughts on testing:
Never ever depend on a test to hire someone. Always follow with a solid interview, and background check. There are folks who can blow away a test and couldn't poor pee out of a boot with instructions written on the heal. Likewise, there are some very good techs out there that have troubles with testing.
Always use both a written and a hands on tests if possible. Our test bank uses more than two hundred questions and picks fifty at random, from groups to get the right content balance.
Missed questions can provide a lot of information about the individual. Not so much that they missed the question, but the thought process that led to missing the question. We have several safety related questions that have more than one correct answer, until you consider safety. Likewise, I have maintenance questions that are designed to detect experience.
I am not at liberty to offer our test to the public. There is too much at stake for those who take this test.
When I was in the mills, I often tested new hires prior to the interview. I found that it does not take a large involved test to sort out the good people. But, if you have 200 applicants, and three jobs, an involved test helps.
Oddly enough, most often the results of the written tests, and hands on tests confirm each other. I always expected to see a good many breakouts, where someone would have trouble on a written test, then sail through a hands on. So far, that is not the norm, or even common.
We happen to have a very impressive set of laboratories to work with. So hands on, be it motor controls, PLC, Instruments, or even lighting circuits, is easy for us to set up. The hands on part is time weighted and I can pick from any number of built in, or added faults. I try to use real MCC's/Starters, with a typical PLC for the Motor controls/PLC tests. We have five "plants" a boiler, and two small digesters (we can make paper from chips on site.) The plants include pH treatment, DeMin plant, Crystallizer, a Batch Process, and a Level/Flow/Temp water plant on single loop controllers. The DeMin, crystallizer, and batch are all on PLC's with a control room running RSView. The pH is also on single loop controllers.
To say the least, my new job has been a joy. Seeing the next generation of electricians on their way up is a lot of fun. Still at testing time, I often test people that I have worked with/around for years. Some have worked for me. Fortunately, I only evaluate, I do not pass or fail anyone, only record progress. The decisions are made by the company that we are testing for at the time. (Several local mills use this service.) For that reason, I am very careful to make sure that the tests have definite answers/solutions. Any personal judgment is avoided.
...a WAG would be 
