Together, our results suggest that increasing the frequency of formative evaluations may not help teachers to improve and caution against interpreting large increases in evaluation scores as evidence of improved teacher effectiveness.

Difference-in-difference estimates show no gains in student learning. If anything, the opposite. In the year teachers were told they would be re-evaluated, their students scored 0.055 standard deviations lower on national exams. There also were no changes to student and parent ratings of teachers.

The catch? That's a naive before/after comparison of teacher evaluation scores. What actually happened to their teaching and to student learning? Not much.

Teachers who were re-evaluated raised their evaluation scores massively: by a full standard deviation. That's well beyond what regression to the mean predicts.

Chile evaluates its public school teachers through a national system meant to be formative. A 2011 reform required teachers rated "basic," the second-lowest of four ratings, to be re-evaluated after two years instead of four.

What happened?

We look at whether increasing evaluation frequency can help lower-performing teachers improve using nationwide data from Chile between 2005-2015.

Thanks to my awesome co-authors @emilykpenner.bsky.social and @yujialiu.bsky.social as well as the many folks who have helped to improve this project since I started it my first year of grad school!

4/4

That’s far from the last word, though, and I think there’s a lot more to learn when it comes to understanding why four-day weeks often don’t achieve their intended retention benefits and what else districts can do to address their staffing challenges.

3/4

While we can’t say for sure why the schedule change seemed to drive teachers away, it’s an important data point and consistent with a growing body of research. Across studies in several states now, there’s not much evidence that shortening the school week improves teacher retention.

2/4

Thank you Alli! I have learned so much about this topic from your research already and I can’t wait to see all that is to come from the SPARC center. As our paper highlights, retention challenges are particularly acute in special education roles of all types. Glad you all are tackling this head on.