Ed Next Research Finds NCLB Has Produced Substantial National Gains In Math Skills

How has the No Child Left Behind (NCLB) Act affected student achievement? This is no idle question, as the landmark federal law is long overdue for reauthorization. The Obama administration has recently urged Congress to add the issue to its already crowded 2010 agenda, even going so far as to include an additional $1 billion for K–12 education in its budget proposal if the law is reauthorized this year (a wholly symbolic gesture, given that it is Congress that sets spending levels, but one that indicates the administration’s priorities).

Yet heightened attention to NCLB has not produced consensus over its consequences for students. No Child Left Behind was a reauthorization of the Elementary and Secondary Education Act (ESEA), the central federal legislation relevant to K–12 schooling. NCLB dramatically expanded the law’s scope by requiring that states introduce school-accountability systems that applied to all public schools and students in the state. NCLB requires annual testing of students in reading and mathematics in grades 3 through 8 (and at least once in grades 10 through 12) and that states rate schools, both as a whole and for key subgroups, with regard to whether they are making adequate yearly progress (AYP) toward their state’s proficiency goals. Supporters and critics, in their various approaches to discerning NCLB’s impact, share a significant problem: because NCLB applies to all public school students, researchers lack a suitable comparison group and so have been unable to distinguish the law’s effects from the myriad other factors at work over the past eight years.

The new research we present below takes on this challenge. Our basic insight is that the test-based accountability provisions that are the defining characteristic of NCLB did not come from nowhere, but rather were modeled quite closely on reforms adopted by many states in the 1990s. For states with such accountability systems in place before 2002, NCLB’s most important components may have created some logistical headaches but were largely irrelevant. In contrast, NCLB forced the remaining states to enact accountability systems for the first time. We can therefore estimate the impact of NCLB’s accountability mandates by comparing test-score changes in states that did not have NCLB-style accountability policies in place when the law was implemented to test-score changes in those that did.

We find that the accountability provisions of NCLB generated large and statistically significant increases in the math achievement of 4th graders and that these gains were concentrated among African American and Hispanic students and among students who were eligible for subsidized lunch. We find smaller positive effects on 8th-grade math achievement. These effects are concentrated at lower achievement levels and among students who were eligible for subsidized lunch. We do not, however, find evidence that NCLB accountability had any impact on reading achievement among either 4th or 8th graders.

Assessing NCLB

The broad interest in understanding whether NCLB has influenced student achievement, both overall and for key subgroups, has motivated careful scrutiny of trend data from the National Assessment of Educational Progress (NAEP) and other sources. For example, the authors of a report commissioned by the U.S. Department of Education’s Institute of Education Sciences (IES) note that achievement trends on both state assessments and NAEP were “positive overall and for key subgroups” through 2005. Using more recent data, a report by the Center on Education Policy concludes that reading and math achievement as measured by state assessments has increased in most states since 2002 and that there have been smaller but similar patterns in NAEP scores. Both reports were careful to stress that these national gains are not necessarily attributable to the effects of NCLB.

Other studies have taken a less sanguine view of these achievement gains, arguing that they are misleading because states have made their assessment systems less rigorous over time. University of California scholar Bruce Fuller and colleagues, for example, document a growing disparity between student performance on state assessments and NAEP since the introduction of NCLB and conclude that “it is important to focus on the historical patterns informed by the NAEP.” Using NAEP data on 4th graders, they conclude that the growth in student achievement has actually slowed since the introduction of NCLB.

Turning to the broader literature on school accountability, several researchers have evaluated the achievement consequences of the accountability systems states developed during the 1990s. One study by Martin Carnoy and Susanna Loeb of Stanford, which was based on state-level NAEP data, found that the within-state growth in math performance between 1996 and 2000 was larger in states with higher values on an accountability index, particularly for African American and Hispanic students in 8th grade. Another study, by Eric Hanushek and Margaret Raymond, both also at Stanford, evaluated the impact of school-accountability policies on state-level NAEP math and reading achievement measured by the difference between the performance of a state’s 8th graders and that of 4th graders in the same state four years earlier. They classified states as having either “report-card accountability” or “consequential accountability.” Report-card states provided a public report of school-level test performance. States with consequential accountability both publicized school-level performance and attached consequences to that performance. Hanushek and Raymond found that the introduction of consequential accountability within a state was associated with increases in NAEP scores.

Both of these studies suggest that NCLB-style accountability provisions may increase student achievement and also demonstrate how state-level NAEP data can be used to evaluate accountability systems. The analysis described below effectively extends this important work to cover the more recent state accountability reforms that were compelled by NCLB.

Research Design

Given the various social, economic, and educational factors at work before and after NCLB was implemented, it is difficult to draw strong conclusions about the policy’s impact from a simple comparison of achievement trends before and after enactment of the law. For example, the nation was suffering from a recession around the time NCLB was implemented, which one might expect would have reduced student achievement in the absence of other forces. At the same time, other national education policies and programs were in place that may also have influenced student achievement.

Perhaps the central challenge in evaluation research is to identify a plausible comparison group that was unaffected by the intervention under study. In the case of NCLB, this is particularly difficult, as the policy simultaneously applied to all public schools in the United States.

We address this issue by comparing trends in student achievement across states that had varying degrees of prior experience with state school-accountability policies similar to those brought about by NCLB. The intuition behind this approach is that NCLB represented less of a “treatment” in states that had already adopted NCLB-like school-accountability policies prior to 2002. To the extent that NCLB-like accountability had either positive or negative effects on measured student achievement, we would expect, once NCLB had been implemented, to observe those effects most distinctly in states that had not previously introduced similar policies.

This strategy relies on the assertion that pre-NCLB school-accountability policies were comparable to NCLB—that is, that the two types of accountability regimes are similar in the most relevant respects. The fact that many state officials criticized NCLB, arguing that it duplicated their prior accountability systems, suggests the functional equivalence of the two sets of policies. To ensure that this is the case and relying on a number of different sources, we evaluated the comparison states according to whether the features of their pre-NCLB accountability policies closely resembled the key aspects of NCLB. We found that they were in fact quite similar.

As an additional check on the validity of our treatment and comparison groups, we used our research design to estimate the impact of NCLB accountability on outcomes that we would not expect to be affected, such as the state-level average poverty rate and median household income. The fact that our method does not find any “effect” of NCLB on such outcomes suggests that these states can serve as a plausible comparison group for isolating the impact of NCLB accountability.

We implement our research design in a more fine-grained manner than simply comparing achievement trends in the treatment and comparison states. We define the treatment as the number of years without prior school accountability between the 1991–92 academic year and the onset of NCLB. Hence, states with no prior accountability have a value of 11. Illinois, which adopted its policy in the 1992–93 school year, would have a value of 2. Texas would have a value of 4 since its policy started in 1994–95, and Vermont would have a value of 9 since its program began in 1999–2000. This method implies that the larger the value of this treatment variable, the greater potential impact of NCLB. The total effect we report is the impact of NCLB accountability in 2007 for states with no prior accountability relative to states that adopted school accountability in 1997 (the mean adoption year among states that adopted accountability prior to NCLB).

It is important to note that this research design will capture the impact of the accountability provisions of NCLB, but not the impact of other NCLB components such as the Reading First program or its Highly Qualified Teacher provisions. Additionally, our estimates will identify the impact of NCLB-induced school-accountability provisions on states without prior accountability policies. To the extent that one believes that states that expected to gain the most from accountability policies adopted them prior to NCLB, one might view the results we present as an underestimate of the average effect of school accountability.

Data

read on… http://educationnext.org/evaluating-nclb/