In recent years, talk of academic “achievement gaps” between students of different racial, ethnic, linguistic, or socioeconomic backgrounds has become increasingly controversial for education policy researchers and advocates. Critics argue that this framing stigmatizes historically marginalized students by confirming ugly stereotypes, particularly the toxic, racist implication that lower average student achievement is linked to students’ own inadequacies or effort.

Advocates for the framing counter that the measurement, aggregation, and comparison of student achievement levels serve to measure structural inequities and dysfunction in how U.S. public education serves diverse groups of students. That is, achievement gaps measure school-, district-, state-, and country-wide disparities in helping children learn content over time and subsequently reach a series of academic benchmarks. These advocates maintain that in public education—as in any other public policy system—clear data on how well schools help students succeed are necessary to guard against educational systems slipping into well-worn and unjust racial and socioeconomic hierarchies.

However, a new study from University of Nebraska–Lincoln looking at the academic achievement of English learners (ELs) serves as a reminder that the utility of studying—and trying to close—these gaps depends entirely on making sure that they are measured correctly.

English Learners Are Unique

Under No Child Left Behind and its successor, the Every Student Succeeds Act, states have been required to measure all students’ progress in math and language arts multiple times from late elementary to middle school and once more in high school. These standardized assessments seek to measure all students and student identity groups against common benchmarks for academic achievement—which makes them the data backbone for identifying and analyzing achievement gaps.

This intuitively seems a good approach for measuring how well schools serve students of relatively static groups. If fourth-grade students from a particular racial group score persistently poorly on math tests in a school, district, or state, policymakers might reasonably devote additional resources to—and insist on greater accountability for—narrowing those gaps.

But this approach is somewhat less effective for English Learners. As I wrote in my recent TCF report, A New Federal Equity Agenda for Dual Language Learners and English Learners, achievement gaps between ELs and non-ELs work differently, because

these gaps are largely a function of how the Every Student Succeeds Act (ESSA) tracks [English learners’] performance. By definition, ELs lack proficiency in English. Once they become English proficient, they are no longer classified as ELs. Thus, it stands to reason that ELs—who have limited English proficiency—will be unable to fully demonstrate their knowledge of math, English language arts, and other subject areas when they are tested on these subjects in English.

In other words, states are required to identify students as ELs if their language proficiencies are likely to make it difficult for them to succeed academically in English-only academic settings. With ELs legally defined by their still-emerging English proficiencies, it should come as no surprise, then, that data routinely show persistent achievement gaps between ELs and non-ELs.

But unlike students of a particular racial background, for instance, students in the EL student group exit the group if they meet their state’s metric(s) defining “English proficiency.” That is, while a student who is African-American does not, over time, cease to be African-American, ELs frequently reach proficiency in English and thereby cease to be counted as ELs. Critically, as these students reach proficiency in English, their academic achievement tends to improve. And since this improvement generally happens as they cease to be ELs, that means that achievement gaps between the group of students currently identified as ELs and non-ELs are inevitable. The ELs group is always, by definition, limited to those students who have not yet reached English proficiency levels that would make it likely that they would be scoring well on academic assessments in English. What’s more, the higher academic achievement of former ELs—students who have become English-proficient and left the group—then contributes to the non-EL side of the ledger, adding to the EL/non-EL achievement gap.

In other words, this is an instance in which federal education policies define an achievement gap into existence. This doesn’t accurately portray most ELs’ trajectories in school, which means it doesn’t provide the public, policymakers, or researchers with a meaningful view into how well public schools serve ELs.

New Data Confirms the Problem

In October, Educational Researcher published a study from University of Nebraska–Lincoln researchers that illustrates the perils of the current policies for tracking ELs’ academic progress. Given the aforementioned problems with measuring the academic progress of students designated as ELs against the progress of non-EL students, the researchers instead compared the academic performance of children who speak a non-English language at home with monolingual, English-dominant children. By sidestepping state designations of which students are currently ELs, the researchers were able to study the academic outcomes of a broader range of linguistically diverse students during the period when No Child Left Behind was the primary federal legislation governing U.S. K–12 schools (2002–2015).

And, indeed, this adjustment of variables produced a different story about the performance of children learning English in U.S. schools. The researchers examined fourth and eighth grade reading and math scores on the National Assessment of Educational Progress (NAEP); while they still found achievement gaps between multilingual students and monolingual students, the researchers wrote, “there was a significant decrease in the magnitude of achievement gaps over time.” What’s more, “the achievement gap narrowed more in recent years than it did initially.”

In other words, during the No Child Left Behind era, even as the EL versus non-EL achievement gap appeared recalcitrantly wide, the study found that multilingual students were actually making real progress.

Some states were more successful than others at narrowing gaps during this period. The researchers noted that “states with larger multilingual populations had smaller achievement gaps and states with larger percentages of multilingual students who speak Spanish had greater reductions in the achievement gap over time.” It is possible that states whose schools served many multilingual students were committing more resources and developing institutional knowledge for helping these students succeed. Meanwhile, the prevalence of Spanish in U.S. culture, society, and schools may mean that schools found it easier to acquire curricula and launch programs to meet Spanish-dominant multilingual students’ needs.

Policies for Building a Complete Story

The study echoes findings from earlier research comparing the progress of multilingual students with monolingual English-dominant children. Its findings are a welcome corrective to longstanding narratives stigmatizing ELs and their academic performance.

And yet, these findings have real limits, and are insufficient for endorsing particular EL policies or reforms. First: trendlines based on tests given in just fourth and eighth grades do not adequately capture multilingual students’ (or ELs’) progress compared to their monolingual (or non-EL) peers.

Second: by focusing on the performance of “multilingual students” instead of ELs, the study groups together a number of linguistically diverse students, including: current ELs, former ELs, and other students who speak a non-English language at home but were never classified as ELs. While this avoids the problems mentioned above with how public policies define “ELs” and “non-ELs,” it also imposes limits by obscuring differences in achievement within the multilingual student group. For instance, what if the gap-closing narrative uncovered in this study reflects improved performance from a subset of the multilingual student group, such as former ELs, while other multilingual students continue to struggle?

Fortunately, there are some straightforward policy ideas for making progress on these problems. To get a clearer picture of linguistically diverse students’ achievement, schools and policymakers should rely on data from more regular standardized assessments. Annual tests provide critical data for measuring ELs’ progress over time. And yet, while schools already give annual math and literacy assessments, states generally only publish data from these on the performance of current ELs and their non-EL counterparts, and thus simply replicate the performance gap written into the distinction between the two groups.

What to do? Well, as I suggested in A New Federal Equity Agenda for Dual Language Learners and English Learners, federal policymakers should require states to add a category to their public reporting: they should also share data on the progress and performance of former ELs and long-term English learners (LTELs). That is, when an EL student reaches proficiency in English and (usually) improves their academic performance, these improvements would be captured separately in a new “former ELs” student group. Further, EL students who do not reach English proficiency after roughly six years in school would be flagged as LTELs.

Adding these categories of achievement data would allow the public, researchers, and policymakers to see how schools are truly serving ELs over time. Instead of focusing on closing academic achievement gaps during the period when ELs are still developing their proficiencies in English, for instance, leaders would be able to examine how well these students performed after they reached full proficiency. This would be better and fairer for students, families, and teachers alike: if former ELs were still struggling academically after being deemed proficient in English, schools could be required to invest more resources and improve the opportunities they provide these students.

Indeed, in places (California, New York, Chicago, Oregon, and beyond) where these data are already gathered, there is some evidence that former ELs outperform monolingual English-dominant students who were never designated as ELs. The trouble, however, is that LTELs tend to have particularly poor academic outcomes.

If other states, districts, and schools found similar patterns in their data after tracking former ELs’ performance, leaders could focus their accountability systems on ensuring that more EL students reach proficiency within six years and ensuring that they succeed academically when they become former ELs. In places where former ELs were significantly underperforming their monolingual English-dominant peers, accountability systems could require schools and districts to focus on closing these gaps. In places where large percentages of ELs were not reaching English proficiency after six years—becoming long-term English learners—systems could require districts and schools to overhaul the language instruction these students were receiving.

This framing—tracking different elements of progress for linguistically diverse student groups depending on their place in the trajectory towards achieving proficiency—isn’t nearly as neat and tidy as the old achievement gap framing between ELs and non-ELs. And yet, the bulk of evidence suggests that it would be a fairer, more constructive way to focus school and district accountability mechanisms.