Mathematica Policy Research has a report out looking at a small group of teachers who earned their teaching credentials through the American Board for the Certification of Teacher Excellence program.
ABCTE is a national alternative route that allows candidates to bypass most education coursework.
Students taught by the 25 English language-arts teachers studied did not have statistically different achievement results on the state test than those students taught by a "matched" comparison group on non-ABCTE teachers with similar characteristics. But students of the 18 ABCTE teachers scored lower than their counterparts in math by about 25 percent of a standard deviation. (The report says that means the classroom average would have been about 10 percentile points lower in the ABCTE-taught classes).
This is one of the first studies to look at the impact of teachers who earn this credential on student achievement, but the small sample size means the results probably shouldn't be extrapolated beyond this particular group of teachers and applied to the ABCTE program as a whole, said Steven Glazerman, one of the Mathematica analysts who conducted the study.
And because this isn't a "randomized" study, where students are randomly assigned to teachers, it's not clear whether other factors might be influencing the results. (Do ABCTE teachers tend to be assigned, or to seek out, high-poverty schools? Do principals assign them different kinds of students?)
The ABCTE folks are, unsurprisingly, not thrilled by the results. “We had hoped for a much larger and more balanced sample size and we were disappointed that this paper was not submitted for peer-review," said ABCTE president David Saba in a statement. "ABCTE has issued over 1,900 certifications but only 30 ABCTE certified teachers were studied by Mathematica. ... This sample size is just too small to conclude anything except that this deserves further study.”
Saba also noted that many of the teachers studied were veterans who needed to become fully certified in order to stay in the classroom, not the career-changers and new teachers that the group targets.
When I asked Glazerman if this study is the tip of the iceberg where ABCTE is concerned, he sighed. "I would love it if there were an iceberg," he said.
One of the challenges, he explained, is that the number of ABCTE teachers who work in tested grades and subjects and have enough sequential years of student-achievement data to be studied is not great enough to get to the sample you'd need to make broad generalizations about the program.