One pro to such a test for teachers would be to ensure that teachers do indeed have knowledge of what they are teaching. It also ensures that teachers aren't forgetting the things they learned in school that are outside of their subject area. This is important as our need for cross-curriculum education increases. All teachers need to know a basic knowledge set as well as a basic skills set. The downside would be cost and time. Teachers would have to take time out of the classroom to fulfill the requirement. School, states, and other government agencies would have to find a way to support the cost of testing the teachers nationwide. As it is, most states require teachers to show they are continuing their personal education and training in order to renew their teaching license. While there isn't a basic skills test, most states do have a way to ensure that their teachers are staying sharp, up to date in their practices, and retaining a basic knowledge set.