Teacher Looping and the Fine Balance of Pitching Education Reforms

A psychologist and an economist walk into a debate …

Illustration of the same teacher writing at two chalk boards

Adam Grant:

Photo of Adam Grant
Adam Grant

Too many education reform efforts are expensive and ultimately ineffective. In Hidden Potential, I wrote about a practice that’s remarkably affordable and has rigorous evidence behind it. It’s looping—staying with the same teacher for multiple years.

A few weeks ago, I saw an unusually thoughtful critique from Matthew Kraft, a leading education economist. I was excited to learn from his expertise, and I think you will be too, so I invited him to do an exchange.

Matthew Kraft:

Photo of Matthew A. Kraft
Matthew A. Kraft

Hi Adam – Thanks for the gracious offer to have a conversation about your New York Times op-ed on Looping.

It is probably worth saying up front for readers that we both think looping makes sense. It leverages the power of relationships, which are at the heart of teaching. My colleagues and I have studied looping and found it increases test scores, raises attendance, and decreases disciplinary incidents. So, what is my deal?

My gut reaction to the op-ed wasn’t even really about looping per say; it was more about the perils of pitching education policy reforms. I’ll frame my concerns as “the three worries.”

Worry #1: Magnitude I’m worried we might be overselling the benefits that looping brings to students. There have been three independent studies that examine repeat teacher-student matches in the U.S. and one in Chile. Remarkably, they all find consistently small effects, on average.

North Carolina: 0.024 standard deviations

Indiana: 0.015 standard deviations

Tennessee: 0.019 standard deviations

Chile: 0.02 standard deviations

I’m on record as arguing, “We can aim high without dismissing as trivial those effect sizes that represent more incremental improvement.” It’s attractive because there are few financial costs, but, yikes, these are small.

The U.S. studies largely evaluate accidental looping—think a handful of kids having the same teacher by accident, not the entire class. Maybe intentional looping has bigger effects, but the results in Chile where looping is done more systematically don’t suggest so.


Adam Grant:

In your fascinating paper, you find that “Effects increase with the share of repeat students in a class.” That makes me wonder if accidental looping is underestimating the effects of entire classes staying together.

Regardless, you’re right that the effect sizes are small. As you know well, small effects can be of great practical significance when aggregated across many millions of students. Psychologists have proposed that small effects are especially meaningful when the outcome is difficult to influence and the intervention is minimal. I think looping meets both criteria.

First, the outcome of academic achievement is very difficult to move as well as overdetermined by a large number of factors. I suspect we’d see stronger effects of looping on attitudes and behaviors that are more proximal and malleable than standardized test scores. Sure enough, the excellent new paper that you flagged from Chile shows effects that are more than twice as strong for boosting students’ attendance and reducing disruptive classroom behaviors. I’d also underscore that the effect sizes are often larger for struggling teachers and students. That said, they’re still small in absolute terms.

Second, the existing research on looping focuses on a minimal intervention—a second year with the same teacher pales in comparison to longer-term looping. In Finland and Estonia, six years together are common. In the U.S., Montessori students often stay with a teacher for at least three years, and Waldorf students frequently have the same teacher for five to eight years.

As you note, we don’t know whether there are growing benefits or diminishing returns of looping for longer periods of time. That’s an empirical question, but I’d place my bet on growing benefits, at least for a third and fourth year.

As one illustration, consider this email that I received last week from a teacher named Natalie Laino:

I am a 29-year educator, and the most impactful and amazing years of my career were when my co-teaching partner and I looped with our students. We taught at a Title 1 school with many second language learners and decided to loop …. [O]ur students were showing tremendous growth …. [P]arents and families began asking administration if the loop could continue. It not only continued to third grade, but … through sixth grade. … The relationships and family that we created continue today, and the students from our first looping class are now turning 30 years old. We attend graduations, weddings, and catch up when traveling across the states as they have settled their adult lives from coast to coast.

It’s hard to imagine just two years together leading to that kind of lasting bond. We’ve barely scratched the surface of studying the conditions for unleashing the potential in looping, and I’d love to see randomized controlled trials or natural experiments testing the effects of longer-term looping. Have you ever considered doing one with Waldorf or Montessori?


Matthew Kraft:

No, but we should make it happen! My kids went to a preschool that used many Montessori practices, and we all loved it. But I have to say, as a parent and a researcher I’m very skeptical of looping for six consecutive years. Like most things in education, I image there are diminishing returns.

Worry #2: Unintended Consequences My next worry is that despite good intentions, looping may do more harm than good in this moment. Teacher burnout and turnover are the highest we have seen in decades. Is asking teachers to switch grades or subjects the next year and prep for all new classes on top of everything they have endured during the pandemic reasonable right now? Certainly, there will be some teachers that would embrace this opportunity, but for others it might be the straw that broke the camel’s back.


Adam Grant:

I’ve also been wondering about the potential burdens associated with the added prep. This is another empirical question—and it’s one where my field of organizational psychology has relevant evidence. My hunch is that any short-term costs will be outweighed by longer-term benefits for teacher well-being.

  1. By enhancing teacher effectiveness, looping is likely to prevent empathic distress and boost self-efficacy—a well-established buffer against burnout. These upsides may be more pronounced for low-performing teachers, who are at the greatest risk of burnout and appear to gain the most from looping.
  2. Looping is a source of task and skill variety—which the job enrichment literature has long linked to heightened satisfaction and motivation.
  3. Looping may also allow teachers to see their prosocial impact over an extended period of time—my own research suggests that this is likely to promote positive affect and protect against burnout.


Matthew Kraft:

Great points, real potential upside as well!

Worry #3: Misattribution Perhaps my biggest worry is that the framing of why we should do looping—because Finland and Estonia do it and they have high test scores—is misleading.

In education circles, the misattribution of increases (or decreases) in test scores on the National Assessment of Educational Progress, known as the NAEP, is so pervasive that we have a word for it: “mis-NAEP-ery.” People even play “mis-NAEP-ery” bingo when new test scores drop!

I’m worried that we’ve slipped into the realm of “mis-PISA-ery” by looking at the high scores for Finland and Estonia on the Program for International Student Assessment (PISA) and ascribing them, in part, to looping.

It certainly is possible looping is contributing to their success, but we just don’t know that. Looping is common in Italy as well, but Italy scores well below the U.S. on the PISA.

There is a long history of education reformers casting a star-struck gaze at Finland’s performance on international tests and saying, let’s do what they do! This too has earned a nick-name as the “cult of Finland.”

But factors outside of education systems are the primary drivers of differences in test scores. Education systems still matter, but ascribing one specific education practice—out of the infinite number of interconnected practices that make up their systems—as one of the secrets to their success is fraught.


Adam Grant:

We’re in full agreement here. We shouldn’t attribute Finland or Estonia’s educational success to any one active ingredient. Due to space constraints, I only managed to squeeze in a paragraph on other ingredients in the NYT excerpt, but it’s a major focus of chapter 7 of the book—which features looping as one element of a much larger system and culture focused on professionalizing teaching and developing the potential in all students. I treat looping as part of a bundle of practices that can help to advance the broader goal of building meaningful, personalized relationships between teachers and students.


Matthew Kraft:

You are a master communicator of social science. I don’t envy the challenge you had in boiling down the rich and nuanced discussion of a full chapter into a short op-ed that catches the readers’ attention with a single, clear message. You’ve put looping on the radar of a lot more folks and might have lit the spark to get it going in the U.S. But I worry that busy policymakers might only read the headline and the first few paragraphs and commit “mis-PISA-ery” / join the “cult of Finland”.

So, Adam, my big question to you is, “Am I worrying too much?”


Adam Grant:

I appreciate the kind words, I love the question, and I’m not sure of the answer. On the one hand, I wouldn’t want to oversell looping. It’s not a panacea, and setting unrealistic expectations can lead to “honeymoon-hangover” effects and ultimately to change fatigue and cynicism.

On the other hand, in my experience, knee-jerk rejection of new ideas is far more common than reckless adoption. The education world desperately needs more experimentation, and we should start with policies that have clear benefits—especially when they’re low-cost. That’s what excites me about looping. What advice would you have for schools that are ready to try it?


Matthew Kraft:

I’d say start small with a coalition of the willing, talk to teachers and parents, and don’t overpromise.

For looping to work, we will need to have deep teacher and parent involvement in the design and rollout of the policy. Education research is littered with examples of promising policy reforms that have underwhelmed at scale because they lacked teacher input and parent buy-in. Education policy is only as good as the quality of its implementation.


Adam Grant:

That’s a place where education economics and organizational psychology are in strong agreement. Even good ideas fail with bad execution.

Adam Grant is an organizational psychologist at the Wharton School of the University of Pennsylvania. Matthew A. Kraft is an associate professor of education and economics at Brown University.


Last Updated


Notify Me When Education Next

Posts a Big Story

Business + Editorial Office

Program on Education Policy and Governance
Harvard Kennedy School
79 JFK Street, Cambridge, MA 02138
Phone (617) 496-5488
Fax (617) 496-4428
Email Education_Next@hks.harvard.edu

For subscription service to the printed journal
Phone (617) 496-5488
Email subscriptions@educationnext.org

Copyright © 2024 President & Fellows of Harvard College