Here’s why California’s teachers and schools can’t fix low test scores on their own

California’s latest standardized test results have triggered the usual alarm: Why are students underperforming? 

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

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

These numbers look stark, but in context they reveal far more about the conditions California children are growing up in than the quality of classroom instruction.

California educates a disproportionate share of children experiencing housing insecurity. A 2024 analysis found that 4% of California students were homeless, with some counties reaching 16%. The California Department of Education reports 230,443 homeless students statewide, a 26% increase over five years that mirrors broader trends in affordability, overcrowding and displacement. 

Poverty and residential instability suppress academic outcomes across states. Still, California’s much higher share of students facing these hardships and attending public schools — rather than being absorbed into private ones — exerts a downward pressure on statewide scores.

Another defining factor is California’s substantial English learner population. According to the Public Policy Institute of California, current and former English learner students score 16–17 percentage points lower, on average, than peers who were never classified as English learners.

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

Pandemic recovery, too, remains uneven. California’s national assessment results are still below pre-pandemic levels, and the lowest-performing students lost the most ground — an inequity that the Public Policy Institute and CalMatters have repeatedly documented. Chronic absenteeism also has not returned to pre-2020 levels.

Additionally, in some higher-income districts, many of the highest-achieving students now opt out of the state’s standardized testing altogether, meaning statewide averages increasingly reflect a more skewed testing pool.

Who’s not taking the tests?

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

The state and national tests rely almost entirely on public school samples. Private school students — who are disproportionately affluent, stably housed and high-performing — are not included in state averages. According to the California Department of Education, 494,464 students attend private schools statewide, representing 7.8% of all K–12 students. 

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

The exclusion of these students reshapes the public school landscape. Public schools end up serving a much more concentrated population of high-need students, independent of teaching quality. And the fiscal consequences are severe: 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 cost the district roughly $80 million annually, or $20,000 per student. 

Fewer students mean fewer counselors, fewer reading specialists, and fewer supports that help struggling learners succeed. Loss of federal funding also affected English learners and other support services, exacerbating the problem.

Improving the odds

Raising California’s test scores requires solving the right problem. Scores are low because a higher proportion of children live in deep poverty, experience housing instability or homelessness, are learning English, or are attending school inconsistently — and because a significant share of higher-income students is not in the testing pool at all.

Test scores improve when children’s conditions improve. That means expanding stable, affordable housing; adopting and scaling the science of reading statewide; providing targeted, meaningful support for English learners; reducing chronic absenteeism, and stabilizing district funding in communities experiencing enrollment loss.

California’s public schools are doing the most challenging work with the fewest advantages. If we continue judging them without acknowledging who they serve — and who they don’t — we will continue diagnosing the wrong problem and offering the wrong solutions.