The headline of a new study from Matthew A. Kraft (Brown University) and David Blazar (Harvard Graduate School of Education) caught our eye: Intensive, personalized coaching programs can improve teacher performance substantially.

Professional development that works? Well… perhaps. 

The two researchers examined New Orlean's yearlong adaptation of a coaching program from Boston-based MATCH School. Participants spend a week in a summer workshop followed by four one-week sessions of observation and feedback. Importantly, the participants teach a range of grades and subjects, distinguishing the program from more common coaching interventions that focus on early literacy. 

Teachers who got the coaching scored significantly higher than the uncoached teachers on an index of teacher quality that includes classroom observation scores, principal evaluation, and student surveys. In fact, the impact of having been coached exceeded even the impact of a teacher gaining more experience. The difference between coached and uncoached groups was nearly 50 percent higher than the difference between novice and experienced teachers.

Coached teachers outperformed uncoached teachers by 0.59 standard deviations. For comparison, experienced teachers (3+ years experience) outperformed novice teachers (1 or 2 years experience) by a smaller margin of 0.44 standard deviations.

Despite relying on a generally strong methodology, the size of the sample involving only 30 matched pairs tones down our enthusiasm a tad. But more importantly, the sample is restricted to teachers from urban charter schools who wanted to participate in the program—meaning that this approach may not translate well to other settings or less willing groups of teachers.

Still, given how little we know about how to help teachers improve, even preliminary evidence of some ways professional development might become more effective is noteworthy.