An old belief is now reborn: if you don't have a degree in that subject, then you shouldn't teach that subject. Schools and districts are once again recognizing the importance of subject area knowledge. Of course, this would eliminate a lot of Teach for America candidates with business degrees, and it would stop someone with a communications degree from teaching high school English. But in my opinion, and from what I have witnessed lately, it's a rule worth enforcing.
In Texas, if you can pass the subject area test, then you are allowed to certify for that subject. The tests are not very difficult; I passed all four of mine on the first attempt. So, if I tried to certify to teach math, even though I have no subject area knowledge in that subject, and I miraculously passed the test, then I could become certified. No one analyzes my transcript for subject area background, and I could immediately start calling myself a math teacher. This is a very faulty system because I should have been required to complete a number of core classes before standing up before students of my own. I should have a very high grade average in the subject I am teaching.
In urban schools we are inundated with teachers without subject area knowledge. Many of these teachers have never belonged to a formal education program at the university level. Some of them have only had five weeks of serious training via Teach for America. Many others complete their alternative certification through a variety of sources, and almost none of these teachers belong to a professional organization in their teaching field. Those belonging in Kappa Delta Pi, or similar honor society, are likely less than one-percent.
In the very lucrative, for profit, arena of school reform, I suggest a fabulous way to save money: require teachers to know their subject, and carry this proof in their college transcript.