Proficiency is the share of tested students meeting the state's proficiency bar, grades 3–8 combined, one value per school per year, exactly as published in the state files City Fund shared (2019 and 2022–2025; no statewide testing in 2020–21). Enrollment is the school's fall total. Demographic shares are fall enrollment shares from the two shared vintages; the income measure is free/reduced-price lunch.
Every other school in the chosen state, optionally narrowed to the same grade band and sector. They answer: is this school's movement unusual, or is that just what school data does?
The green centre line is the school's own average across its years. The dashed limits are
mean ± 2.66 × average year-to-year move — the standard XmR
("individuals and moving range") construction, where 2.66 converts the average move into a
three-sigma band. A point outside the band is a signal that something changed (the population, the
test, or the reporting), not by itself a judgment about the school.
Each bar is the absolute change from the prior year; its limit is
3.267 × average move. Moves spanning the 2019→2022 pandemic gap are
excluded from the averages and drawn hollow. With only four usable points per school, all limits
are provisional (the method prefers ten or more) — exactly why more shared history is on the
partner data-request list.
Demographic shares get the alignment project's pre-registered screen instead: any move larger than 15 percentage points is flagged for the governance committee before scores are run.