The texts for several of the courses I teach provide test banks and I see them as both good and bad. I often find errors, not only in the answer keys, but in the grammar and spelling as well. Frequently I find typographical mistakes too. I usually rewrite some of the choices on the multiple choice test banks because there are too many "all of the above"s or "both A & B" type answers. On the other hand, the test banks save me time and also give me ideas for questions to ask the students during lecture. I have also adapted some of the multiple choice test bank questions into completion tests or short answer tests.