That the U.S. has a shortage of math and science teachers is well known. But the problem is deeper still: while students suffer not only because of the math and science teachers they don't have, many states set unacceptably low expectations for the science teachers they do have.

Based on their high school science licensure requirements, many states seem to presume that it is all the same to teach anatomy, electrical currents and Newtonian physics. In addition to licensing in single subjects such as biology and chemistry, most states also allow certification in "general science," with requirements that do not ensure that all secondary biology, chemistry and physics teachers have mastered the content they teach. By clinging to a loose definition of "science teacher," many states treat specialized science teachers as interchangeable.

In The All-Purpose Science Teacher, NCTQ takes a state-by-state look at preparation and credentialing requirements for secondary science teachers and finds some pretty big loopholes. All but 11 states allow secondary science teachers to obtain general-science certifications or combination licenses across multiple disciplines. In most cases, these teachers need only pass a general-knowledge science exam that does not ensure subject-specific knowledge.

States say districts--especially rural districts--need the flexibility to assign teachers across the science disciplines. And the U.S. Department of Education has bought into this mindset, allowing teachers with "broad field" science certification to be considered HQT. But this approach only masks and perpetuates the problem, rather than expanding strategies that improve the science teacher pipeline, such as distance learning or alternate route programs such as UTeach.

NCTQ has heard from a couple of states that their teachers with general science certification are, in fact, only able to teach introductory, general science courses. But without such a restriction clearly stated in the certification requirements, regardless of the intent, the loophole remains.

See which states earned red, yellow and green lights in NCTQ's latest traffic light report here.