NCES Data Explained: What CCD and EDFacts Actually Measure
Published April 17, 2026 · Methodology
Every number on this site comes from one of two federal datasets. Understanding what they measure, and what they don't, is the difference between making an informed school choice and being misled by a vanity metric.
The Common Core of Data (CCD)
CCD is the NCES directory of every public school, district, and state education agency in the United States. It is collected annually from state education agencies and published by the National Center for Education Statistics. Every public school is legally required to report.
What CCD gives us: school name, address, NCES ID, grade range, school type (regular, vocational, alternative, special education), charter and magnet status, Title I status, total enrollment by grade, race and ethnicity counts, free/reduced-price lunch eligibility, and teacher counts.
CCD is the gold standard for structural facts about a school. If you want to know how many students attend a school or whether it's a charter, CCD is the source.
EDFacts
EDFacts is a federal collection that gathers state-reported academic performance data. States send their standardized test results and graduation statistics to the U.S. Department of Education, which publishes consolidated files.
What EDFacts gives us: percent of students proficient in reading and math by grade band, four-year adjusted cohort graduation rates, participation rates, and achievement gaps by demographic subgroup.
EDFacts data is typically district-level rather than school-level, because many states do not publish school-level results for privacy or methodological reasons. When we show a proficiency rate on a school profile, it reflects the district average applied to that school. This is a known limitation.
What the Data Cannot Tell You
- Individual student growth. Proficiency is a snapshot. It cannot tell you whether students are learning faster or slower than expected.
- Teacher quality. No federal dataset measures instructional effectiveness directly.
- School climate. Bullying, student happiness, arts programs, extracurriculars, these require local visits and community sources.
- Cross-state comparability. A 70% proficiency rate in Massachusetts and a 70% rate in Mississippi reflect different standards.
How We Use This Data
OpenSchoolData shows CCD enrollment and characteristics directly at the school level, and EDFacts proficiency and graduation rates at the district level, clearly labeled. We do not compute synthetic composite scores. If a metric is not available, we mark it "N/A" rather than fill in an estimate. Read our full methodology for more detail.
Where to Dig Deeper
For the raw data, visit the NCES Common Core of Data portal and EDFacts. The Urban Institute also publishes a free education data API that powers much of this site's backend.
Frequently Asked Questions
The National Center for Education Statistics is the U.S. Department of Education's primary data agency. It collects and publishes data on every public school in the country through the Common Core of Data (CCD).
EDFacts is a federal collection system that gathers state-reported academic performance data, including proficiency rates on standardized tests and high school graduation rates. It is typically published with a one to two year lag.
No. Each state sets its own proficiency threshold, so a 60% proficiency rate in one state may not mean the same thing as 60% in another. Comparisons within a state are reliable; across states, they are not.
CCD enrollment data is typically published 18-24 months after the school year ends. EDFacts assessment data often lags by two or more years. This is the normal release cadence for validated federal education data.
This explainer summarizes the two primary federal data sources used throughout OpenSchoolData.