The multivariate normality assumption of the true score model was judged reasonable for all domains and grades¶

Claim · All claims
Evidence · 1 study · associational r2 · q2
Currency · newest study 2026 · checked against its sources 2026-10-09 (automated, 1 of 1 entry) · not reviewed by a person · recheck by 2029: tool and model accuracy changes quickly

Subclaims¶

q2 i? Q-Q plots, CDF curves, and model residuals indicate some deviations from the straight line at the tails, but the authors conclude the model normality assumption was met for all domains and grades. → Wei He 2026

Evidence¶

Wei He 2026¶

Wei He, NWEA Psychometrics and Analytics. (2026). Achievement and Growth Norms for Spanish MAP Reading Fluency Foundational Skills. NWEA. https://www.nwea.org/research/publication/achievement-and-growth-norms-for-spanish-map-reading-fluency-foundational-skills-report/

q2 · i? · associational · r2

Graphical normality checks (histograms, Q-Q plots, CDF curves, and residuals from model estimation) presented for grade K Phonological Awareness in Figures 3.1-3.4, with the report stating figures for other domains were similar. This is a visual judgment, not a formal statistical test.

"While the Q-Q plots indicate some deviations from the straight line at the tails, the figures suggest that normality assumptions of the model seem reasonable. The figures for other domains were similar to those for the Phonological Awareness scores for grade K."

Discussion¶

Related Claims¶

• Given assumption violations and the uniformity factor, the authors judge the LDF method more likely accurate and superior to ICC for this performance assessment — related
• The assessment violates IRT assumptions of unidimensionality and local independence, which the authors identify as a likely cause of the method discrepancy — related
• Q-Q plots, CDF curves, and residual checks support the joint normality assumption underlying the multivariate true score model for the course-specific tests. — a narrower finding that bears on this claim
• The multivariate normality assumption of the norming model was judged met for all domains and grades, despite some tail deviations in Q-Q plots — possibly the same claim (merge candidate)
• 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