Q-Q plots, CDF curves, and residual checks support the joint normality assumption underlying the multivariate true score model for the course-specific tests.¶
Claim · All claims
Evidence · 1 study · associationalr2·q2
Currency · newest study 2019 · checked against its sources 2026-10-09 (automated, 1 of 1 entry) · not reviewed by a person · overdue for a recheck since 2022: tool and model accuracy changes quickly
Subclaims¶
Reading the evidence codes
q is the design tier, i the impact, n the sample, and the kind with its r
the rigour judged within that kind: what each code means.
This claim: no standardized effect is recorded in observations/ for it yet, so no benchmark reading is possible.
q2 i? Normality was judged a reasonably good approximation for Algebra 1 from histograms, Q-Q plots, and CDFs, with similar graphs supporting Geometry and Algebra 2. → Thum 2019
Evidence¶
Thum 2019¶
Thum, Y. M., & He, W. (2019). Achievement and growth norms for course-specific MAP® Growth™ Algebra 1, Geometry, and Algebra 2 tests. NWEA Research Report. Portland, OR: NWEA. https://www.nwea.org/research/publication/achievement-and-growth-norms-for-course-specific-map-growth-algebra-1-geometry-and-algebra-2-tests/
q2 · i? · associational · r2
Graphical normality examination (Figures 3.1–3.4 and Appendix A) of RIT scores and true score model residuals for Algebra 1, Geometry, and Algebra 2. The report states the Q-Q plots show data close to the reference line except at the extremes and that the Appendix graphs for Geometry and Algebra 2 resemble those for Algebra 1.
"The Q-Q plots indicate that most of the data fall close to the 45-degree reference line except at the very low and high ends, suggesting that normality was a reasonably good approximation"
Discussion¶
Related Claims¶
- The multivariate normality assumption of the true score model was judged reasonable for all domains and grades — a broader claim this one bears on
- The multivariate normality assumption of the norming model was judged met for all domains and grades, despite some tail deviations in Q-Q plots — related
- Normality assumptions of the true score model appeared reasonable for the course-specific tests — possibly the same claim (merge candidate)
- The outcome data met t-test assumptions: Lilliefors normality (Lo < Lt for both classes) and variance homogeneity (F count 0.579 < F table 1.84) — related
Page metadata
| Field | Value |
|---|---|
type |
claim |
id |
course-specific-norms-normality-supported |
title |
Q-Q plots, CDF curves, and residual checks support the joint normality assumption underlying the multivariate true score model for the course-specific tests. |
description |
Q-Q plots, CDF curves, and residual checks support the joint normality assumption underlying the multivariate true score model for the course-specific tests. |
status |
review |
evidence_strength |
moderate |
newest_evidence |
2019 |
source_checked |
2026-10-09 |
recheck_by |
2022 |
generated |
by process:wiki-ingest on 2026-10-08 |
trust |
unverified — no one has confirmed this page's content |
sources |
1 — thum-2019 |
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