Where our data comes from, how current it is, what a rating does and doesn’t tell you, known limitations, how to report an error, and a dated log of corrections we’ve made. This page is a plain factual account, not a marketing pitch — see Methodology and How Ratings Work for the full calculation walkthrough.
Every number on this site traces back to one of four public sources. Nothing is estimated by us beyond the specific per-pupil-spending modeling disclosed on the Methodology page.
| What it covers | Source |
|---|---|
| District names, LEAIDs, enrollment, school counts, contact info | NCES Common Core of Data (CCD) |
| Ratings for districts in 19 states (see list below) | Each state's own current assessment program |
| Ratings for districts in the remaining states | U.S. Dept. of Education EDFacts collection |
| ZIP-to-district assignment | US Census TIGER/Line district boundaries + Census ZCTA centroids |
| District boundary maps | US Census TIGER Web Services (live) |
The 19 states with their own assessment overlay: AZ, CA, CO, FL, GA, IL, IN, MA, MD, MN, MO, NC, NJ, NY, TN, TX, VA, WA and WI. Every zip page states the exact source and school year behind its own rating. The full dataset, including per-district state percentile and source year, is downloadable as CSV on the Open Data page under CC BY 4.0.
We would rather state a source's age honestly than imply everything is equally fresh. It isn't:
A rating is the average of a district's reading and math proficiency rates — the share of students scoring proficient or above on state assessments — percentile-ranked against every other district in the same state, and converted to a 1–10 score.
It does not measure:
Because it is a within-state percentile, a rating is not comparable between states — a 7/10 in one state reflects a different underlying proficiency level than a 7/10 in another. Hawaii operates as a single statewide school district, so there is no in-state peer group to rank against; Hawaii pages show “Not comparable” rather than a number.
If something on this site looks wrong, email [email protected] with:
What happens next: we check the report against our source data and the authoritative source you provided. If it's a data error, we correct it and, for substantive corrections, add a dated entry to the changelog below. We aim to respond within 5 business days.
On 2026-08-10 and 2026-08-11 we ran a data-integrity audit across the site and corrected several classes of error. In the interest of transparency, here is what was wrong and what changed:
Some district pages stated a specific student-teacher ratio and a specific per-pupil spending figure as if measured for that district. Neither is a district-level measurement in our source data: the ratio was a constant per state (for example, every Alaska ZIP page showed the same 11:1 regardless of district), and the spending figure came from a state-level table. We reworded these sentences to attribute the figures to the state, which is what they actually are.
A page's FAQ text stating district enrollment and school counts had, on pages where neither NCES nor the page's own data held a real figure for that district, been filled in with generic round numbers (for example, "5,500 students across 10 schools") instead of being left blank. Those invented figures were removed rather than replaced with another guess.
On 6,001 district pages, the FAQ text stated an enrollment and school count that disagreed with the structured district-data block on the same page. We checked both figures against NCES: the structured data block was correct in 5,906 of those cases and the FAQ text was correct in none of them. The FAQ text was resynced to match the verified figures (or, where no source had a real figure, the sentence was dropped — see above).
Five ZIP codes (03215 Waterville Valley NH, 03593 Randolph NH, 54850 La Pointe WI, 85341 Lukeville AZ, and 55111 in Saint Paul MN) carried a federal placeholder code meaning “district not defined” and displayed the literal text “School District Not Defined”; each was researched individually and assigned to its real district. A sixth, 82930 (Evanston, Uinta County, Wyoming), had been assigned to a Utah district; it was reassigned to Uinta County School District 1, the Wyoming district that actually serves it. Separately, one more ZIP, 40032 (La Grange, Oldham County, Kentucky), had been assigned to an Indiana district about 100 miles away; it was corrected to Oldham County School District, the same district as its neighboring Kentucky ZIP codes.
On a set of pages generated by cloning a template from another ZIP, the “nearby ZIP codes are served by…” text still named the template's neighboring districts rather than the page's own. For example, a Lukeville, Arizona page (on the Mexican border) named two districts as its nearest neighbors that were actually roughly 200 miles north and in the Phoenix metro area. We recomputed real neighboring districts from each page's own coordinates against every other district's ZIP coverage.
The meta/description text on some pages named the wrong city in its locality parenthetical — on template-cloned pages, sometimes the template's originating city rather than the page's own. We corrected the locality to match each page's own district-data block.
Our Methodology and How Ratings Work pages previously stated that every rating was built entirely from the federal EDFacts collection. That was inaccurate for roughly half the site: districts in 19 states are rated from that state's own current assessment data instead, as individual ZIP pages already correctly disclosed. We corrected the two site-level pages to describe both sources and added an explicit note that ratings are not comparable between states.