The recent exchange with Gary Lear about reliability and validity really highlights one of the major problems with these instruments and their usage. THIS IS IN NO WAY MEANT TO COMMENT ON GARY, BUT ON THE GENERAL SITUATION.
Even the companies that train and certify people to administer these tests are turning out people with a very poor grasp or understanding of the research, the theories IN CONTEXT, or the statistical aspects of the tests. This may not be an issue for some.