When advocates say, “We all know what’s happening,” and are only armed with anecdotes and not data, it is hard for policymakers to distinguish between what is a one-time experience versus a trend that requires action.

While my son was in a Title I elementary school in the Raleigh, NC area, I watched firsthand as immigrant students and students from low-income backgrounds were passed over for accelerated math placement in middle school, while dozens of students from the more affluent elementary feeder schools were placed in those courses. If you or your children attend one of these schools, you know.

Even with the most compelling stories of qualified and eager students being passed over for advanced math coursework, advocates like myself weren’t able to change policy until education researchers showed definitively that the school was “leaking” gifted math students out of the advanced math pipeline. Thanks to statewide assessment data, BEST NC found that thousands of students, perhaps tens of thousands of students, were deprived of access to advanced math coursework each year in North Carolina.

Advanced coursework access in early and middle grades is important. Students who take algebra by eighth grade have dramatically higher chances of succeeding in college. These classes are also gateway courses to AP/ STEM courses, STEM college degrees, and high-paying jobs in STEM fields — of which many Black and Latino students are shut out, as a recent Ed Trust report shows.

And what happens when a bright student is put in a class below their ability? They lose interest — the data shows that too.

In 2018, North Carolina passed the first law in the nation that ensures qualified students from fourth grade through high school are automatically placed in advanced math courses. In the first year of implementation, the policy had a tremendous impact on access to advanced math in North Carolina. During the summer of 2018, 2,100 rising eighth grade students were “placed up” into Math I (typically a ninth grade class) for the following school year after having been originally placed in a lower math class. Another 6,000+ students in other grades were estimated to be placed into advanced courses.

As a result of the policy, each of those thousands of students were enrolled in a course that they should have been placed in because of their mathematical ability. But it wasn’t until advocates had consistent, comparable data at the statewide level to show that the stories were not just anecdotal anomalies that North Carolina policymakers answered the call and passed this policy — unanimously

This is just one example of how reliable statewide assessments play an important role in ensuring public schools meet the needs of individual students, including those who are being underserved. Even if a parent knows that their child scored well on their end-of-grade exam, they may not always feel empowered to speak up when their child isn’t placed in the right course. In fact, their school may not even communicate that their child could and should have been in Math I in eighth grade, for example.

North Carolina’s initial policy requires districts to place students based solely on whether they scored at the highest tier of their end-of-grade exam in the prior year. Moving forward, my organization hopes to expand the placement criteria to multiple years of data and, ideally, rely on more robust data that uses multiple measures to predict student success in advanced coursework.

Data quality is essential for education equity. Without valid, reliable data that we can look at across a state or district, we can’t see which challenges are most crucial and solvable. Assessment data and data transparency are essential tools to shine a light on the most pressing gaps in educational opportunity.

Brenda Berg is the President and CEO of BEST NC (Business for Educational Success and Transformation in North Carolina), a nonprofit, nonpartisan coalition of over 100 business leaders with a focus on making education in North Carolina the best in the nation.