One of the trendy buzzwords in education lately is “de-tracking.” Tracking is the idea of separating public school students by achievement levels such that some students take more advanced courses and others take more basic courses (or remedial courses). Tracking has been specifically blamed for creating an achievement gap between students of different races which means the debate on the topic has quickly become heated. Here’s how the Washington Post reported on it last summer:

An emotional, racially charged debate over whether to sort students into higher and lower tracks that has unfolded in school districts across the country in recent years is now underway on its biggest stage yet, as the state of California considers a new math framework.

Advocates for the new California math guidelines say “de-tracking,” or mixing together students of varying academic performance, can help all students, particularly those who would have languished in lower-level classes. It can also unravel racial segregation inside schools. Almost everywhere, White and Asian American students are more likely to be placed in higher tracks, with Black and Latino students more likely to be placed in lower tracks.

But many parents — especially those of high-achieving students — are opposed.

As mentioned, California has been considering a new statewide math framework aimed at increasing equity in part by eliminating tracking of students prior to high school:

“The inequity of mathematics tracking in California can be undone through a coordinated approach in grades 6–12,” reads a January 2021 draft of the framework. “In summary, middle-school students are best served in heterogeneous classes.”

Not coincidentally, the same California math framework is also focused on other buzz-wordy topics such as equity, bias and anti-racism. I wrote about some of that here last May.

California’s statewide focus on de-tracking was at least partly modeled after a similar effort in San Francisco. But the claim that eliminating tracking will close the achievement gap isn’t as conclusive as some would like to suggest. Tom Loveless, formerly of the Brookings Institution, published his own look at the San Francisco de-tracking experiment back in March. He concluded the evidence it succeeded was pretty thin.

SFUSD declared detracking a great success, claiming that the graduating class of 2018–19, the first graduating class affected by the policy when in eighth grade, saw a drop in Algebra 1 repeat rates from 40% to 8% and that, compared to the previous year, about 10% more students in the class took math courses beyond Algebra 2. Moreover, the district reported enrollment gains by Black and Hispanic students in advanced courses…

Families for San Francisco, a parent advocacy group, acquired data from the district under the California Public Records Act (the state’s version of Freedom of Information Act). The group’s analysis, available here, calls into question the district’s assertions. As mentioned previously, repeat rates for Algebra I dropped sharply after the elimination of Algebra I in eighth grade, but whether the reform had anything to do with that is questionable. The falling repeat rate occurred after the district changed the rules for passing the course, eliminating a requirement that students pass a state-designed end of course exam in Algebra I before gaining placement in Geometry. In a presentation prepared by the district, speaker notes to the relevant slide admit, “The drop from 40% of students repeating Algebra 1 to 8% of students repeating Algebra 1, we saw as a one-time major drop due to both the change in course sequence and the change in placement policy.”

The claim that more students were taking “advanced math” classes (defined here as beyond Algebra II) also deserves scrutiny. Enrollment in calculus courses declined post-reform. The claim rests on a “compression” course the district offers, combining Algebra II and Pre-Calculus into a single-year course. The Families for San Francisco analysis shows that once the enrollment figures for the compression course are excluded, the enrollment gains evaporate. Why should they be excluded? The University of California rejected the district’s classification of the compression course as “advanced math,” primarily because the course topics fall short of content specifications for Pre-Calculus.

More to the point, enough time has passed since the San Francisco effort that it’s now possible to see how the kids who started under the new de-tracking regime actually performed. You can click here for my description of those results but the bottom line is that the achievement gap between black and white students and also between Hispanic and white students actually got worse in San Francisco.

All of that background came to mind today when I saw a reference on Twitter to a new working paper on the impact of tracking in Texas schools. You can download the full paper (which hasn’t been peer reviewed or published yet) here but I’ll jump to the conclusion:

In this paper, we use detailed administrative data from Texas to create several measures of within-school tracking for grades 4 through 8 for almost every public school in Texas for the 2010-11 to 2018-19 school years. Our data-driven approach allows us to capture both formal and informal tracking within schools, enabling us to provide a comprehensive picture of tracking, including: how much tracking there is across schools and by grade, how schools operationalize tracking, which schools are more likely to track, and how tracking is related to student performance.

… in contrast to the popular perception, we find that the amount of ability sorting that takes place within schools is far greater than the amount of ability sorting that occurs across schools. In addition, we find that within-school sorting based on prior test scores is far greater than within-school sorting based on race/ethnicity and SES…

Finally, when we examine the implications of tracking for future educational outcomes, we find that while exposure to tracking in elementary and middle is not strongly associated with test score growth for students at the bottom of the initial achievement distribution, exposure to tracking in middle school is positively associated with test score growth for students at the top, suggesting that tracking increases inequities in educational outcomes but does not otherwise harm low-achieving students on average.

You could read this as proof that tracking increases the achievement gap. And if that’s your only concern then then de-tracking would presumably reduce that gap. But the key point is that tracking seems to have helped the kids at the top without harming those at the bottom. If that’s true then de-tracking wouldn’t actually help anyone. It would only bring students closer together by limiting the achievement of the kids who are really good at math and who benefit from the advanced classes. Other than pure ideological spite, why would any state want to pursue a policy that did that?