Student Attrition Is A Core Feature Of School Choice, Not A Bug

The issue of student attrition at KIPP and charter schools is never far beneath the surface of our education debates. KIPP’s critics claim that these schools exclude or “counsel out” students who aren’t doing well, thus inflating student test results. Supporters contend that KIPP schools are open admission with enrollment typically determined by lottery, and they usually cite a 2010 Mathematica report finding strong results among students in most (but not all) of 22 KIPP middle schools, as well as attrition rates that were no higher, on average, than at the regular public schools to which they are compared.*

As I have written elsewhere, I am persuaded that student attrition cannot explain away the gains that Mathematica found in the schools they examined (though I do think peer effects of attrition without replacement may play some role, which is a very common issue in research of this type).

But, beyond this back-and-forth over the churn in these schools and whether it affected the results of this analysis, there’s also a confusion of sorts when it comes to discussions of student attrition in charters, whether KIPP or in general. Supporters of school choice often respond to “attrition accusations” by trying to deny or downplay its importance or frequency. This, it seems to me, ignores an obvious point: Within-district attrition - students changing schools, often based on “fit” or performance - is a defining feature of school choice, not an aberration.

A Look At The Changes To D.C.'s Teacher Evaluation System

D.C. Public Schools (DCPS) recently announced a few significant changes to its teacher evaluation system (called IMPACT), including the alteration of its test-based components, the creation of a new performance category (“developing”), and a few tweaks to the observational component (discussed below). These changes will be effective starting this year.

As with any new evaluation system, a period of adjustment and revision should be expected and encouraged (though it might be preferable if the first round of changes occurs during a phase-in period, prior to stakes becoming attached). Yet, despite all the attention given to the IMPACT system over the past few years, these new changes have not been discussed much beyond a few quick news articles.

I think that’s unfortunate: DCPS is an early adopter of the “new breed” of teacher evaluation policies being rolled out across the nation, and any adjustments to IMPACT’s design – presumably based on results and feedback – could provide valuable lessons for states and districts in earlier phases of the process.

Accordingly, I thought I would take a quick look at three of these changes.

School Grades For School Grades' Sake

I have reviewed, albeit superficially, the test-based components of several states’ school rating systems (e.g., OH, FL, NYC, LA, CO), with a particular focus on the degree to which they are actually measuring student performance (how highly students score), rather than school effectiveness per se (whether students are making progress). Both types of measures have a role to play in accountability systems, even if they are often confused or conflated, resulting in widespread misinterpretation of what the final ratings actually mean, and many state systems’ failure to tailor interventions to the indicators being used.

One aspect of these systems that I rarely discuss is the possibility that the ratings systems are an end in themselves. That is, the idea that public ratings, no matter how they are constructed, provide an incentive for schools to get better. From this perspective, even if the ratings are misinterpreted or imprecise, they might still “work."*

There’s obviously something to this. After all, the central purpose of any accountability system is less about closing or intervening in a few schools than about giving all schools incentive to up their respective games. And, no matter how you feel about school rating systems, there can be little doubt that people pay attention to them. Educators and school administrators do so, not only because they fear closure or desire monetary rewards; they also take pride in what they do, and they like being recognized for it. In short, my somewhat technocratic viewpoint on school ratings ignores the fact that their purpose is less about rigorous measurement than encouraging improvement.

The Irreconcilables

** Also posted here on “Valerie Strauss’ Answer Sheet” in the Washington Post

The New Teacher Project (TNTP) has a new, highly-publicized report about what it calls “irreplaceables," a catchy term that is supposed to describe those teachers who are “so successful they are nearly impossible to replace." The report’s primary conclusion is that these “irreplaceable” teachers often leave the profession voluntarily, and TNTP offers several recommendations for how to improve this.

I’m not going to discuss this report fully. It shines a light on teacher retention, which is a good thing. Its primary purpose is to promulgate the conceptual argument that not all teacher turnover is created equal – i.e., that it depends on whether “good” or “bad” teachers are leaving (see here for a strong analysis on this topic). The report’s recommendations are standard fare – improve working conditions, tailor pay to “performance” (see here for a review of evidence on incentives and retention), etc. Many are widely-supported, while others are more controversial. All of them merit discussion.

I just want to make one quick (and, in many respects, semantic) point about the manner in which TNTP identifies high-performing teachers, as I think it illustrates larger issues. In my view, the term “irreplaceable” doesn't apply, and I think it would have been a better analysis without it.

Labor Market Behavior Actually Matters In Labor Market-Based Education Reform

Economist Jesse Rothstein recently released a working paper about which I am compelled to write, as it speaks directly to so many of the issues that we have raised here over the past year or two. The purpose of Rothstein’s analysis is to move beyond the talking points about teaching quality in order to see if strategies that have been proposed for improving it might yield benefits. In particular, he examines two labor market-oriented policies: performance pay and dismissing teachers.

Both strategies are, at their cores, focused on selection (and deselection) – in other words, attracting and retaining higher-performing candidates and exiting, directly or indirectly, lower-performing incumbents. Both also take time to work and have yet to be experimented with systematically in most places; thus, there is relatively little evidence on the long-term effects of either.

Rothstein’s approach is to model this complex dynamic, specifically the labor market behavior of teachers under these policies (i.e., choosing, leaving and staying in teaching), which is often ignored or assumed away, despite the fact that it is so fundamental to the policies themselves. He then calculates what would happen under this model as a result of performance pay and dismissal policies – that is, how they would affect the teacher labor market and, ultimately, student performance.*

Of course, this is just a simulation, and must be (carefully) interpreted as such, but I think the approach and findings help shed light on three fundamental points about education reform in the U.S.

What Florida's School Grades Measure, And What They Don't

A while back, I argued that Florida's school grading system, due mostly to its choice of measures, does a poor job of gauging school performance per se. The short version is that the ratings are, to a degree unsurpassed by most other states' systems, driven by absolute performance measures (how highly students score), rather than growth (whether students make progress). Since more advantaged students tend to score more highly on tests when they enter the school system, schools are largely being judged not on the quality of instruction they provide, but rather on the characteristics of the students they serve.

New results were released a couple of weeks ago. This was highly anticipated, as the state had made controversial changes to the system, most notably the inclusion of non-native English speakers and special education students, which officials claimed they did to increase standards and expectations. In a limited sense, that's true - grades were, on average, lower this year. The problem is that the system uses the same measures as before (including a growth component that is largely redundant with proficiency). All that has changed is the students that are included in them. Thus, to whatever degree the system now reflects higher expectations, it is still for outcomes that schools mostly cannot control.

I fully acknowledge the political and methodological difficulties in designing these systems, and I do think Florida's grades, though exceedingly crude, might be useful for some purposes. But they should not, in my view, be used for high-stakes decisions such as closure, and the public should understand that they don't tell you much about the actual effectiveness of schools. Let’s take a very quick look at the new round of ratings, this time using schools instead of districts (I looked at the latter in my previous post about last year's results).

The Education Reform Movement: Reset Or Redo?

Our guest author today is Dr. Clifford B. Janey, former superintendent for the Newark Public Schools, District of Columbia Public Schools, and Rochester City School District. He is currently a Senior Weismann Fellow at the Bankstreet College of Education in New York City, and a Shanker Institute board member.

For too many students, families, and communities, the high school diploma represents either a dream deferred or a broken contract between citizens and the stewards of America's modern democracy. With the reform movement’s unrelenting focus on testing and its win/lose consequences for students and staff, the high school diploma, which should signify college and work readiness, has lost its value.

Not including the over seven thousand students who drop out of high school daily, the gap between the percentage of those who graduate and their readiness for college success will continue to worsen the social and income inequalities in life. Recent studies report that America has the highest number of people (46.2 million) living in poverty since data collection began in 1959. While poverty and its conditions have been unforgiving, policy makers and education reformers have largely ignored this reality. Rebuttals to this argument are interesting, but, without fundamental change, the predictable growth within the ranks of poverty will continue.

A framework within which solutions will thrive requires a redo of the national reform focus, not merely a reset of existing efforts—including teacher evaluation systems, closing low performing schools (and opening up new ones that are at best marginally better), and increasing the opportunity for mayoral control (which still commands attention but with little assurance of transparency).

Quality Control In Charter School Research

There's a fairly large body of research showing that charter schools vary widely in test-based performance relative to regular public schools, both by location as well as subgroup. Yet, you'll often hear people point out that the highest-quality evidence suggests otherwise (see here, here and here) - i.e., that there are a handful of studies using experimental methods (randomized controlled trials, or RCTs) and these analyses generally find stronger, more uniform positive charter impacts.

Sometimes, this argument is used to imply that the evidence, as a whole, clearly favors charters, and, perhaps by extension, that many of the rigorous non-experimental charter studies - those using sophisticated techniques to control for differences between students - would lead to different conclusions were they RCTs.*

Though these latter assertions are based on a valid point about the power of experimental studies (the few of which we have are often ignored in the debate over charters), they are dubiously overstated for a couple of reasons, discussed below. But a new report from the (indispensable) organization Mathematica addresses the issue head on, by directly comparing estimates of charter school effects that come from an experimental analysis with those from non-experimental analyses of the same group of schools.

The researchers find that there are differences in the results, but many are not statistically significant and those that are don't usually alter the conclusions. This is an important (and somewhat rare) study, one that does not, of course, settle the issue, but does provide some additional tentative support for the use of strong non-experimental charter research in policy decisions.

The Weighting Game

A while back, I noted that states and districts should exercise caution in assigning weights (importance) to the components of their teacher evaluation systems before they know what the other components will be. For example, most states that have mandated new evaluation systems have specified that growth model estimates count for a certain proportion (usually 40-50 percent) of teachers’ final scores (at least those in tested grades/subjects), but it’s critical to note that the actual importance of these components will depend in no small part on what else is included in the total evaluation, and how it's incorporated into the system.

In slightly technical terms, this distinction is between nominal weights (the percentage assigned) and effective weights (the percentage that actually ends up being the case). Consider an extreme hypothetical example – let’s say a district implements an evaluation system in which half the final score is value-added and half is observations. But let’s also say that every teacher gets the same observation score. In this case, even though the assigned (nominal) weight for value-added is 50 percent, the actual importance (effective weight) will be 100 percent, since every teacher receives the same observation score, and so all the variation between teachers’ final scores will be determined by the value-added component.

This issue of nominal/versus effective weights is very important, and, with exceptions, it gets almost no attention. And it’s not just important in teacher evaluations. It’s also relevant to states’ school/district grading systems. So, I think it would be useful to quickly illustrate this concept in the context of Florida’s new district grading system.

The Test-Based Evidence On New Orleans Charter Schools

Charter schools in New Orleans (NOLA) now serve over four out of five students in the city – the largest market share of any big city in the nation. As of the 2011-12 school year, most of the city’s schools (around 80 percent), charter and regular public, are overseen by the Recovery School District (RSD), a statewide agency created in 2003 to take over low-performing schools, which assumed control of most NOLA schools in Katrina’s aftermath.

Around three-quarters of these RSD schools (50 out of 66) are charters. The remainder of NOLA’s schools are overseen either by the Orleans Parish School Board (which is responsible for 11 charters and six regular public schools, and taxing authority for all parish schools) or by the Louisiana Board of Elementary and Secondary Education (which is directly responsible for three charters, and also supervises the RSD).

New Orleans is often held up as a model for the rapid expansion of charter schools in other urban districts, based on the argument that charter proliferation since 2005-06 has generated rapid improvements in student outcomes. There are two separate claims potentially embedded in this argument. The first is that the city’s schools perform better that they did pre-Katrina. The second is that NOLA’s charters have outperformed the city’s dwindling supply of traditional public schools since the hurricane.

Although I tend strongly toward the viewpoint that whether charter schools "work" is far less important than why - e.g., specific policies and practices - it might nevertheless be useful to quickly address both of the claims above, given all the attention paid to charters in New Orleans.