A new study looking at the impact of professional development (PD) on student learning throws more cold water on its efficacy, at least the notion that providing teachers PD in math pedagogy can do much to improve either teacher knowledge or, more importantly, student achievement.

In a study undertaken by the Institute for Education Sciences, researchers examined a two-year PD effort designed to boost middle school math scores. While the PD did bolster 7th grade teachers' pedagogical content knowledge of rational numbers, it ultimately had almost no impact on students' performance, or, for that matter, teachers' general content knowledge. Although the IES study was focused on pedagogical content knowledge, it's not as if the math content taught in this study was fluff.

The study found that "students taught by teachers with higher knowledge (i.e., straight content coupled with pedagogical knowledge) scores exhibited significantly higher achievement." Surprisingly, that finding is pretty much a first in the literature.

Several takeaways: First, if PD is not a panacea for teacher improvement, education schools need to produce teachers who are more capable coming off the blocks by providing much more solid content preparation. Second, given the weakness of several hundred thousand current math teachers, the authors' plug for investigation of PD emphasizing straight content knowledge deserves fast-tracked attention.