It has been my observation that there is widespread use of "test banks" in the career colleges. The test banks are provided by the publisher of the textbooks. Instructors also draw from other sources.
Some programs are writing their own tests.
One big problem is content validity. The tests are really supposed to match the course objectives. Sometimes instructors simply "teach to the test" in so called "reviews" in order to patch over the problem and avoid post testing riots!
Professional teachers know that "teaching to the test" scientifically skews the results. It is better to discard questions post test based upon statistics. (Of couse one can argue that it is better to throw them out before the test is given.)
David Leon Cooper, MS (Ed Adm)