Four Key Learnings from Recent Research on Charter Schools

Two new studies on charter school performance were released this week and hold implications for our work to grow more great schools for Indianapolis students. Both show the positive academic impact charter schools have on student learning and the importance of quality at the authorizer and operator level.

The study that received the most national headlines was from Stanford University’s Center for Research on Education Outcomes (CREDO). This was CREDO’s third national study of charter school performance, building on similar studies from 2009 and 2013. Analyzing data from 2015-2019, CREDO found that students who attend public charter schools make more academic growth than their peers who attend traditional public schools. 

The second study was from Joseph Ferrare, Joseph Waddington, and Mark Berends, who represent the University of Washington, the University of Kentucky, and the University of Notre Dame, respectively. Their study examined charter authorizer quality in Indiana using data from 2008-2018. They found that schools authorized by the Indianapolis Mayor’s Office produce significant positive impacts on student achievement while the performance of schools authorized by other Indiana authorizers varied considerably.

Both of these studies come on the heels of CREDO’s 2022 study that specifically examined the performance of Indianapolis charter schools. Using data from 2017-2019, CREDO found that Black, Latino, and low-income students attending Indianapolis charter schools made significantly more academic progress than their peers in local traditional public schools. 

At The Mind Trust, we constantly analyze academic data and independent research to ensure our strategies align with the evidence. When it comes to charter school performance, we must ask, “For whom do charter schools work best and under what conditions?” When taken together, these two studies provide tremendous insights and a roadmap for how to accelerate student learning in Indianapolis. Four of those insights are summarized below.

1. Charter schools produce significant academic gains for Black, Latino, and low-income students. 

Measuring academic outcomes by student groups, like race and income, is essential to getting a full picture of school performance. In past studies, CREDO found notable, positive results for Black, Latino, and low-income students who attend charter schools. That trend continued in their 2023 study on national charter school performance. 

This year, CREDO went one step further than most studies by analyzing academic progress for students of color who also come from low-income families. The national results were striking.

Black students from low-income families achieved learning gains equivalent to:

• 37 days of additional learning in reading and
• 36 days of additional learning in math.

Latino students from low-income families achieved:

• 36 days of additional learning in reading and
• 30 days of additional learning in math. 

CREDO’s 2022 study on Indianapolis charter schools found even more pronounced results.

When compared to their peers in local traditional public schools, Black students in Indianapolis charter schools gained:

• 86 days of additional learning in reading and
• 144 days of additional learning in math. 

Meanwhile, Latino students in Indianapolis charter schools gained:

• 73 days of additional learning in reading and
• 109 days of additional learning in math.

Low-income students attending Indianapolis charter schools also outgained local traditional public school students. They achieved:

• 63 days of additional learning in reading and
• 112 days of additional learning in math. 

Perhaps no other education reform over the past quarter century has led to such consistent and significant academic gains at scale for historically marginalized student groups. Given this, we have a moral imperative to continue increasing the number of Black, Latino, and low-income students in Indianapolis who attend high-quality charter schools.

2. Charter school networks outperform single site schools.

The Mind Trust launched our current strategic plan two years ago with a top-line goal of tripling student proficiency within Indianapolis Public Schools’ boundaries by 2027. In order to accomplish this ambitious goal, our school incubation strategy is focused on replicating high-quality charter and innovation schools by expanding high-performing networks. 

The new national CREDO study affirms our strategic direction. Researchers found that “charter networks bring a greater learning benefit to students compared to standalone charter schools.” According to CREDO’s data set, charter school networks led students to gains of 27 additional days of learning in reading and 23 additional days of learning in math compared to traditional public school students. These reading gains were three times greater than for single site schools and math gains were eight times greater.

In addition, the Ferrare, Waddington, and Berends study found similar results. Charter networks – especially those authorized by the Indianapolis Mayor’s Office – produced significant positive impacts on student learning when compared to standalone charter schools.

As an example of our revamped strategy to grow charter networks, last fall we announced $2.4 million in Capacity Building Awards to grow four high-quality charter school networks that will collectively be able to serve over 1,600 new students through those investments. We plan to make another round of financial awards later this month that will provide support for additional high-performing networks to serve even more students. 

3. Brick-and-mortar charter schools outperform virtual charter schools. 

Only 6% of the charter school population nationwide attends a virtual charter school. However, virtual schooling options have grown since the onset of the pandemic. This year’s CREDO study builds on mountains of research indicating that virtual schools have substantially negative impacts on student learning.

Certainly, some students thrive when attending a virtual school. Virtual charter schools have a role to play in a diverse school choice landscape. But the evidence is clear: in head-to-head comparisons, brick-and-mortar schools overwhelmingly outperform virtual charter schools. This year’s study looked at over 200 virtual charter schools across the country. The majority showed weaker growth in reading and math when compared to traditional public schools. 

While CREDO did not provide virtual school results specifically for Indiana, the Ferrare, Waddington, and Berends study found that virtual schools in Indiana produce significant negative academic results. Under specific conditions, virtual charter schools might offer a necessary option for certain students. However, when it comes to improving student learning at scale, we must focus on the replication of brick-and-mortar charter networks that have proven track records of performance.

4. Authorizer quality matters.

The most significant finding in the Ferrare, Waddington, and Berends study is that there is great variation in the quality of different authorizers in Indiana. The study found that schools authorized by the Indianapolis Mayor’s Office produce significantly positive impacts on student achievement. Schools authorized by the Indiana Charter School Board do not have a significant positive or negative impact on student learning. Schools authorized by institutions of higher education produce negative impacts on student learning.

Charter schools in Indianapolis are driving massive learning gains, particularly for Black, Latino, and low-income students. This is in large part due to the exceptional authorizing quality from the Mayor’s Office of Education Innovation. Charters outside of Indianapolis have a much more mixed record of performance. This variation in authorizing quality, coupled with the negative impacts of virtual schools, is almost certainly the reason why this year’s CREDO study did not find that Indiana charter schools, on the whole, have either a significant positive or negative impact on student learning. 

The takeaway? The Indianapolis Mayor is directly accountable to voters. During the tenures of three mayors representing both political parties, schools overseen by the Mayor’s Office continue to drive life-changing learning gains for their students. Authorizing matters, and we should strive to implement policies that promote quality authorizing.

Leaning In To What Works 

Recent research on charter school performance reiterates foundational beliefs that have driven The Mind Trust’s work since our founding in 2006. All students, no matter their background, can achieve at high levels given the right conditions. We will continue to align our strategies with the data as we seek to ensure that all students in Indianapolis have access to a life-changing school. 

The evidence is clear: urgently growing the number of students who attend schools with the conditions that produce significant positive impacts on student learning must be a top-priority for The Mind Trust and our broader community.