California teachers can’t fix low test scores on their own

By Jill Stegman, especially for CalMatters

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California’s latest standardized test scores set off the usual alarm bells: Why are students underperforming?

But the familiar narrative—blaming teachers, curriculum, or school culture—misses deeper structural realities behind the numbers.

Only 47% of students met standards in English and 36% met standards in maths, according to 2024–25. California Assessment of Student Performance and Progress results. On National Assessment of Educational Progress exam, only 29% of California 4th graders and 25% of 8th graders scored well in reading and math.

These numbers seem obvious, but in context they reveal much more about the conditions in which California children grow up than the quality of instruction in the classroom.

California educates a disproportionately large share of children who experience housing insecurity. A Analysis for 2024 found that 4% of students in California are homeless, with some counties as high as 16%. The California Department of Education reports 230,443 homeless students nationwide, a 26% increase over five years, reflecting broader trends in affordability, overcrowding and displacement.

Poverty and housing instability depress academic performance across states. Still, the much higher share of California students facing these difficulties and attending public schools — rather than being absorbed into private ones — is putting downward pressure on the state’s results.

Another determining factor is California’s sizeable English language learner population. According to the Public Policy Institute of California, current and former English language students scored 16–17 percentage points loweraverage than peers who were never classified as English learners.

This is not evidence of system failure; it reflects the time and stability needed to learn academic English. California public schools serve more English language learners than any other state. These students need multi-year support, consistent teaching and predictable housing.

The recovery from the pandemic also remains uneven. California’s national assessment scores are still below pre-pandemic levels, and the lowest-performing students have lost the most ground — an inequity that Institute for Public Policy and CalMatters have been documented many times. Chronic absence from work has also not returned to pre-2020 levels.

Also, in some higher-income districts, many of the highest-achieving students now opt out of state standardized testing overall, meaning statewide averages increasingly reflect a more skewed testing group.

Who doesn’t take the tests?

The least-discussed factor may turn out to be the most important: who is not included in California’s test scores.

State and national tests rely almost entirely on public school samples. Students from private schools — which are disproportionately affluent, stable housing and high achievers — are not included in the state averages. According to the California Department of Education, 494,464 students attend private schools nationwide, representing 7.8% of all K–12 students.

In San Francisco, share reaches nearly 30%. A full county breakdown is available here.

Excluding these students is changing the public school landscape. After all, public schools serve a much more concentrated population of high-needs students, regardless of the quality of teaching. And the fiscal consequences are serious: public school funding follows enrollment. When families move to private schools, districts lose revenue.

KQED reports that San Francisco Unified’s loss of 4,000 students it costs the district roughly $80 million a year, or $20,000 per student.

Fewer students means fewer counselors, fewer reading specialists, and fewer supports to help struggling learners succeed. The loss of federal funding also affected English language learners and other support services, exacerbating the problem.

Improving the odds

Raising test scores in California requires solving the right problem. Scores are low because a greater share of children live in deep poverty, experience housing instability or homelessness, learn English, or attend school irregularly—and because a significant share of higher-income students are not in the testing pool at all.

Test scores improve as children improve. This means expanding stable, affordable housing; adoption and scaling of science of reading throughout the country; providing targeted, meaningful support for English language learners; reducing chronic absenteeism and stabilizing district funding in communities experiencing enrollment loss.

California public schools do the most challenging work with the fewest benefits. If we continue to judge them without recognizing who they serve—and who they don’t—we will continue to diagnose the wrong problem and offer the wrong solutions.

This article was originally published on CalMatters and is republished under Creative Commons Attribution-NonCommercial-No Derivatives license.