State Assessment Data Repository Methodology

Data sources

All proficiency results are sourced directly from state education agencies (SEAs) - either from their public websites and data portals, or via formal data requests. The EDC never requests personally identifiable information (PII). Where a state does not publish student tested counts, SEA enrollment or federal EDFacts counts are used as a proxy.

School and district characteristics - names and stable federal identifiers - come from the U.S. Department of Education, chiefly the National Center for Education Statistics (NCES) Common Core of Data and EDFacts.

Public records requests

A core part of this work is identifying gaps in publicly reported results and filing public records (FOIA) requests to fill them - always within each state's laws and each state's own suppression rules. Requests target data that states are expected to hold but do not publish, such as grade × subgroup disaggregation, achievement-level counts (not just "proficient or above"), separate regular and alternate results, counts of students tested, participation rates, and average scale scores.

Assessments included

The repository includes achievement data from the annual statewide summative assessments states use to report to the U.S. Department of Education under Title I of ESEA, limited to Grades 3-8. It does not include alternate assessments, English-language-proficiency assessments, or schools represented by the Bureau of Indian Education. Alongside English-language tests, it includes Colorado's Spanish language-arts assessment (Grades 3-4, 2021 on), Puerto Rico's assessments, and the Spanish-language Texas STAAR.

Changes in assessments

When a state changes a test or how it defines proficiency, that is flagged two ways: variables in the data file mark a changed assessment name or proficiency definition versus the prior year; and the "Notable Events" shown beneath Zelma's figures explain new assessments, cut-score changes, years a test was not administered, and unusually low participation.

Years covered

The earliest available year ranges from 1998 to 2018 depending on the state. Two notes: no state administered assessments in Spring 2020 due to COVID-19, so no data exist for that year; and some states have periodic missing years (often from field-testing a new assessment or 2021 pandemic waivers).

For the exact first and last year of data by state and subject, see our full data availability page.

Suppression & missing data

To protect student privacy under FERPA, states suppress cells that could reveal outcomes for small groups (often fewer than 10 students, though this varies). In the data files, suppressed values are shown as an asterisk (*) and data that were never provided are shown as dashes (--). Where states report ranges, those are retained (e.g. a participation rate of ">.95" becomes ".95-1").

Comparability across states