Duke power was using IQ tests and it was found that some whites working at the firm didn’t place high on the test nor were working as well as blacks, who while they didn’t place high on the test could do a superior job never the less.
Plenty of places use placement tests...you’ve heard of civil service exams or written exams one takes to be able to become firemen or go to police school...right? Many nursing jobs, as part of the application process might require simple calculations tests.
The key is, they can’t be written in such a way that excludes minirities unfairly.
Yes, I know about civil service exams, as well as the lawsuits filed against departments which use them when the "correct" number of minority applicants do not get a passing grade. (Just google for (firefighter or police) exam lawsuit and you get 3 million results)
The way police and fire departments typically deal with such potential situations is by giving minorities "bonus points", or by picking the highest-scoring minorities to fill X% of the slots (even if the highest scoring minorities get test results well below those of rejected white male applicants).