Course grades increasingly measure compliance and executive function; standardized assessment measures knowledge. At population scale, the two diverge — and the gap falls hardest on neurodivergent students.
Two measures of the same student frequently disagree: the teacher-assigned course grade and the standardized assessment of mastery. The divergence is not random noise. Factor-analytic work on nationally-representative student samples shows that teacher-assigned grades load on a distinct “Success at School Factor” — conscientiousness, engagement, and executive function — that is separate from, and only modestly correlated with, tested achievement (Bowers 2011; Willingham, Pollack & Lewis 2002; Brookhart et al. 2016). In plain terms: the grade and the mastery measure are measuring different things, and the gap is largest for students whose executive function is impaired.
If grading penalizes an executive-function/behavior profile, the institutional signature should appear in exclusionary discipline. It does. Using the full Civil Rights Data Collection universe (US Department of Education, Office for Civil Rights; all 52 reporting jurisdictions), students with disabilities (IDEA + Section 504) are 15.9% of enrollment (8.11M of 50.9M students) yet are over-represented in every exclusionary-discipline and physical-intervention outcome. Risk ratio = the rate for students with disabilities ÷ the rate for non-disabled students.
| Outcome | SWD share of outcome | Risk ratio |
|---|---|---|
| Out-of-school suspension | 29.1% | 2.17× |
| In-school suspension | 25.5% | 1.81× |
| Expulsion | 26.1% | 1.87× |
| Referral to law enforcement | 30.8% | 2.35× |
| School-related arrest | 30.9% | 2.36× |
| Seclusion | 78.5% | 19.3× |
| Physical restraint | 81.5% | 23.3× |
| Any restraint or seclusion | 79.4% | 20.4× |
| Corporal punishment | 19.5% | 1.28× |
Corporal punishment shows the smallest disparity (near parity) — reported here for honesty; not every measure is extreme. Per-jurisdiction figures (all 52) are computed and available to research partners.
Full CRDC universe via the Urban Institute Education Data API, page-paginated across all jurisdictions; sex-total and race-total rows only (no double-count); CRDC negative suppression-codes excluded; students with disabilities = IDEA + Section 504. These figures reproduce the published OCR/GAO topline — students with disabilities suspended at roughly twice the rate of peers, and roughly four-in-five of all restraint/seclusion (cf. GAO-19-243). Source data and the per-jurisdiction breakdown are reproducible from the published method.
The Stanford Education Data Archive establishes that academic achievement is measurable at population scale and structurally unequal: state-pooled, economically-disadvantaged students score roughly 2.2 grade-levels below non-disadvantaged peers in math, with comparable gaps by group (SEDA v4.1, grade-cohort-standardized). SEDA carries achievement, not course grades and not a disability subgroup — so it supports the “mastery is measurable; the mis-measurement is the problem” context, while the grade-vs-mastery divergence itself rests on the peer-reviewed factor-analytic literature above.
The fix is not lower standards — it is honest measurement: score demonstrated mastery directly, and report work-habits separately. Trellison's mastery-based math program (algebra through calculus, validated by a deterministic computer-algebra equivalence checker) is the working proof that rigor can be measured engagingly without softening the bar.