First Person

New York City Charter Lotteries: Hey, You Never Know

A few years ago, the New York State lottery’s slogan was “Hey, you never know.”  In its original formulation, the slogan sought to motivate New Yorkers to play the lottery, a game of chance, on the grounds that you never know unless you play if you are a winner.  But the slogan is a double entendre when applied to Caroline Hoxby’s highly-publicized study of the effects of attending a charter school in New York City.  Propelled by Hoxby’s forceful claims about the superiority of lottery-based research on charter schools, much of the mainstream media has concluded that we now know definitively that New York City charter schools outperform their traditional counterparts—in spite of the fact that her study has not undergone a rigorous peer review process that might identify problems in the study and ways of addressing them.  Today, however, an equally forceful critique prepared by Sean Reardon of Stanford University argues that Hoxby’s research is anything but definitive.  Citing flaws in the statistical analysis of the report, Reardon writes that it “likely overstates the effects of New York City charter schools on students’ cumulative achievement … It may be that New York City’s charter schools do indeed have positive effects on student achievement, but those effects are likely smaller than the report claims.”

Reardon is careful to point out that it’s not possible, based on the information provided in Hoxby’s report and associated documents, to judge the extent of the bias in Hoxby’s estimates of charter school effects on student achievement.  More than anything, he calls for reserving judgment until more information about the study, its data and methods are available, and until the study has undergone rigorous peer review.  Until then, he maintains, it would be unwise to rely on the statistics reported in the study, and the inferences Hoxby and her colleagues draw about charter school effects in New York City.     

Here I’ll mention two of the features of Reardon’s critique that I find particularly persuasive.  The first is that Hoxby used an inappropriate set of statistical models to analyze the data, which likely distorts the charter school effects.  You might be surprised to learn that Hoxby used statistical models at all.  If her results are based on comparing students who won a charter school lottery with students who lost the lottery, and the lottery was fair, balanced and random, why would a model be needed?  It seems like the charter school effect would simply be the difference in the outcomes observed for the lottery winners and the lottery losers.  But comparing lottery winners and losers isn’t really estimating an individual causal effect, because an individual student can’t simultaneously be enrolled in a charter school and a traditional public school.  Even in the context of a lottery, or any other kind of study that can capitalize on a randomization process, such as a clinical drug trial, statistical models come into play to allow for inferences about cause-and-effect relationships.  These inferences are always made in relation to a particular statistical model, and all such models have assumptions.

One of the assumptions that is widely recognized is that a statistical model for causal inference should take account of factors that precede selection into the “treatment”—in this case, enrollment in a charter school versus a traditional public school.  If, hypothetically, charter school attendees were wealthier than traditional public school attendees, we’d want to control for wealth to make the charter and traditional school attendees as comparable as possible.  But it’s just as widely recognized that such a statistical model should not take account of factors that are measured after, and hence potentially influenced by, the treatment.  If attending a charter school increased a student’s motivation, and heightened motivation yields better test scores, then we wouldn’t want to control for motivation in a statistical model for the causal effect of going to charter school on test scores.  That kind of control means that the charter and traditional school attendees are no longer comparable at the time that they began attending a charter versus traditional school, which is the critical time.

Reardon demonstrates that this is precisely what Hoxby and her colleagues do in most of their statistical analyses.  For the analyses of charter school effects on test scores in grades four through eight, she controls for achievement in the prior year—achievement that was observed after the lotteries that determined whether a student enrolled in a charter or traditional public school.  The effects of charter school attendance on test scores in grades four through eight are therefore distorted, but to an unknown degree.  This is not a problem for estimates of the cumulative effect of charter school attendance in grades K-3 on third grade test performance, because the statistical models don’t include prior test scores (as there aren’t any before grade three.)  Reardon therefore finds Hoxby’s estimates of the effect of going to charter school in grades K-3 to be more credible than those for grades four through to eight.  However, the K-3 effect is only one-half to one-third as large as the estimated annual effect of charter school attendance in grades four through eight.    

The second issue is estimation of the cumulative effects of charter school attendance.  Hoxby’s report gets a lot of mileage out of the claim that the effects of attending a charter school from kindergarten to grade eight are large enough to close the performance gap between (predominantly white, upper-class) children in Scarsdale and (predominantly minority, low-income) children in Harlem by 66% in English and 86% in math.  Reardon points out that these figures are based on unrealistic extrapolations.  You can’t simply add up the annual effects of attending a charter school from year to year because the gains decay over time.  Moreover, most of the students in the Hoxby study have been in charter schools for only three or four years;  virtually none have been enrolled in charter schools for as many as nine years, and those would only have been enrolled in the very small number of charter schools that have been open that long, and cannot tell us about the long-term effects of attending the much larger number of newer charter schools.  Reardon’s analysis suggests that Hoxby’s estimate of the cumulative effect of attending a charter school from grades four through eight could be exaggerated by as much as 50%.

Are Caroline Hoxby’s estimates of the effects of attending a charter school rather than a traditional public school in New York City accurate?  Maybe.  But based on Sean Reardon’s critique, probably not.  Hey, you never know.

First Person

I’m a principal who thinks personalized learning shouldn’t be a debate.

PHOTO: Lisa Epstein
Lisa Epstein, principal of Richard H. Lee Elementary, supports personalized learning

This is the first in what we hope will be a tradition of thoughtful opinion pieces—of all viewpoints—published by Chalkbeat Chicago. Have an idea? Send it to cburke@chalkbeat.org

As personalized learning takes hold throughout the city, Chicago teachers are wondering why a term so appealing has drawn so much criticism.

Until a few years ago, the school that I lead, Richard H. Lee Elementary on the Southwest Side, was on a path toward failing far too many of our students. We crafted curriculum and identified interventions to address gaps in achievement and the shifting sands of accountability. Our teachers were hardworking and committed. But our work seemed woefully disconnected from the demands we knew our students would face once they made the leap to postsecondary education.

We worried that our students were ill-equipped for today’s world of work and tomorrow’s jobs. Yet, we taught using the same model through which we’d been taught: textbook-based direct instruction.

How could we expect our learners to apply new knowledge to evolving facts, without creating opportunities for exploration? Where would they learn to chart their own paths, if we didn’t allow for agency at school? Why should our students engage with content that was disconnected from their experiences, values, and community?

We’ve read articles about a debate over personalized learning centered on Silicon Valley’s “takeover” of our schools. We hear that Trojan Horse technologies are coming for our jobs. But in our school, personalized learning has meant developing lessons informed by the cultural heritage and interests of our students. It has meant providing opportunities to pursue independent projects, and differentiating curriculum, instruction, and assessment to enable our students to progress at their own pace. It has reflected a paradigm shift that is bottom-up and teacher led.

And in a move that might have once seemed incomprehensible, it has meant getting rid of textbooks altogether. We’re not alone.

We are among hundreds of Chicago educators who would welcome critics to visit one of the 120 city schools implementing new models for learning – with and without technology. Because, as it turns out, Chicago is fast becoming a hub for personalized learning. And, it is no coincidence that our academic growth rates are also among the highest in the nation.

Before personalized learning, we designed our classrooms around the educator. Decisions were made based on how educators preferred to teach, where they wanted students to sit, and what subjects they wanted to cover.

Personalized learning looks different in every classroom, but the common thread is that we now make decisions looking at the student. We ask them how they learn best and what subjects strike their passions. We use small group instruction and individual coaching sessions to provide each student with lesson plans tailored to their needs and strengths. We’re reimagining how we use physical space, and the layout of our classrooms. We worry less about students talking with their friends; instead, we ask whether collaboration and socialization will help them learn.

Our emphasis on growth shows in the way students approach each school day. I have, for example, developed a mentorship relationship with one of our middle school students who, despite being diligent and bright, always ended the year with average grades. Last year, when she entered our personalized learning program for eighth grade, I saw her outlook change. She was determined to finish the year with all As.

More than that, she was determined to show that she could master anything her teachers put in front of her. She started coming to me with graded assignments. We’d talk about where she could improve and what skills she should focus on. She was pragmatic about challenges and so proud of her successes. At the end of the year she finished with straight As—and she still wanted more. She wanted to get A-pluses next year. Her outlook had changed from one of complacence to one oriented towards growth.

Rather than undermining the potential of great teachers, personalized learning is creating opportunities for collaboration as teachers band together to leverage team-teaching and capitalize on their strengths and passions. For some classrooms, this means offering units and lessons based on the interests and backgrounds of the class. For a couple of classrooms, it meant literally knocking down walls to combine classes from multiple grade-levels into a single room that offers each student maximum choice over how they learn. For every classroom, it means allowing students to work at their own pace, because teaching to the middle will always fail to push some while leaving others behind.

For many teachers, this change sounded daunting at first. For years, I watched one of my teachers – a woman who thrives off of structure and runs a tight ship – become less and less engaged in her profession. By the time we made the switch to personalized learning, I thought she might be done. We were both worried about whether she would be able to adjust to the flexibility of the new model. But she devised a way to maintain order in her classroom while still providing autonomy. She’s found that trusting students with the responsibility to be engaged and efficient is both more effective and far more rewarding than trying to force them into their roles. She now says that she would never go back to the traditional classroom structure, and has rediscovered her love for teaching. The difference is night and day.

The biggest change, though, is in the relationships between students and teachers. Gone is the traditional, authority-to-subordinate dynamic; instead, students see their teachers as mentors with whom they have a unique and individual connection, separate from the rest of the class. Students are actively involved in designing their learning plans, and are constantly challenged to articulate the skills they want to build and the steps that they must take to get there. They look up to their teachers, they respect their teachers, and, perhaps most important, they know their teachers respect them.

Along the way, we’ve found that students respond favorably when adults treat them as individuals. When teachers make important decisions for them, they see learning as a passive exercise. But, when you make it clear that their needs and opinions will shape each school day, they become invested in the outcome.

As our students take ownership over their learning, they earn autonomy, which means they know their teachers trust them. They see growth as the goal, so they no longer finish assignments just to be done; they finish assignments to get better. And it shows in their attendance rates – and test scores.

Lisa Epstein is the principal of Richard H. Lee Elementary School, a public school in Chicago’s West Lawn neighborhood serving 860 students from pre-kindergarten through eighth grade.

Editor’s note: This story has been updated to reflect that Richard H. Lee Elementary School serves 860 students, not 760 students.

First Person

I’ve spent years studying the link between SHSAT scores and student success. The test doesn’t tell you as much as you might think.

PHOTO: Photo by Robert Nickelsberg/Getty Images

Proponents of New York City’s specialized high school exam, the test the mayor wants to scrap in favor of a new admissions system, defend it as meritocratic. Opponents contend that when used without consideration of school grades or other factors, it’s an inappropriate metric.

One thing that’s been clear for decades about the exam, now used to admit students to eight top high schools, is that it matters a great deal.

Students admitted may not only receive a superior education, but also access to elite colleges and eventually to better employment. That system has also led to an under-representation of Hispanic students, black students, and girls.

As a doctoral student at The Graduate Center of the City University of New York in 2015, and in the years after I received my Ph.D., I have tried to understand how meritocratic the process really is.

First, that requires defining merit. Only New York City defines it as the score on a single test — other cities’ selective high schools use multiple measures, as do top colleges. There are certainly other potential criteria, such as artistic achievement or citizenship.

However, when merit is defined as achievement in school, the question of whether the test is meritocratic is an empirical question that can be answered with data.

To do that, I used SHSAT scores for nearly 28,000 students and school grades for all public school students in the city. (To be clear, the city changed the SHSAT itself somewhat last year; my analysis used scores on the earlier version.)

My analysis makes clear that the SHSAT does measure an ability that contributes to some extent to success in high school. Specifically, a SHSAT score predicts 20 percent of the variability in freshman grade-point average among all public school students who took the exam. Students with extremely high SHSAT scores (greater than 650) generally also had high grades when they reached a specialized school.

However, for the vast majority of students who were admitted with lower SHSAT scores, from 486 to 600, freshman grade point averages ranged widely — from around 50 to 100. That indicates that the SHSAT was a very imprecise predictor of future success for students who scored near the cutoffs.

Course grades earned in the seventh grade, in contrast, predicted 44 percent of the variability in freshman year grades, making it a far better admissions criterion than SHSAT score, at least for students near the score cutoffs.

It’s not surprising that a standardized test does not predict as well as past school performance. The SHSAT represents a two and a half hour sample of a limited range of skills and knowledge. In contrast, middle-school grades reflect a full year of student performance across the full range of academic subjects.

Furthermore, an exam which relies almost exclusively on one method of assessment, multiple choice questions, may fail to measure abilities that are revealed by the variety of assessment methods that go into course grades. Additionally, middle school grades may capture something important that the SHSAT fails to capture: long-term motivation.

Based on his current plan, Mayor de Blasio seems to be pointed in the right direction. His focus on middle school grades and the Discovery Program, which admits students with scores below the cutoff, is well supported by the data.

In the cohort I looked at, five of the eight schools admitted some students with scores below the cutoff. The sample sizes were too small at four of them to make meaningful comparisons with regularly admitted students. But at Brooklyn Technical High School, the performance of the 35 Discovery Program students was equal to that of other students. Freshman year grade point averages for the two groups were essentially identical: 86.6 versus 86.7.

My research leads me to believe that it might be reasonable to admit a certain percentage of the students with extremely high SHSAT scores — over 600, where the exam is a good predictor —and admit the remainder using a combined index of seventh grade GPA and SHSAT scores.

When I used that formula to simulate admissions, diversity increased, somewhat. An additional 40 black students, 209 Hispanic students, and 205 white students would have been admitted, as well as an additional 716 girls. It’s worth pointing out that in my simulation, Asian students would still constitute the largest segment of students (49 percent) and would be admitted in numbers far exceeding their proportion of applicants.

Because middle school grades are better than test scores at predicting high school achievement, their use in the admissions process should not in any way dilute the quality of the admitted class, and could not be seen as discriminating against Asian students.

The success of the Discovery students should allay some of the concerns about the ability of students with SHSAT scores below the cutoffs. There is no guarantee that similar results would be achieved in an expanded Discovery Program. But this finding certainly warrants larger-scale trials.

With consideration of additional criteria, it may be possible to select a group of students who will be more representative of the community the school system serves — and the pool of students who apply — without sacrificing the quality for which New York City’s specialized high schools are so justifiably famous.

Jon Taylor is a research analyst at Hunter College analyzing student success and retention.