Across 90 grade-subject-level conditions, the three-piece piecewise model showed the lowest deviance for 64% of student-level and 78% of school-level models, outperforming both compound polynomial candidates¶
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Evidence · 1 study · associationalr3·q2
Currency · newest study 2025 · checked against its sources 2026-10-09 (automated, 1 of 1 entry) · not reviewed by a person
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q2 i? In Bayesian model comparison using LOOIC and WAIC, the three-piece piecewise model produced the lowest deviance values in 64% of student-level and 78% of school-level conditions among the three candidate models. → 2025 MAP Growth Norms Technical Manual 2025
Evidence¶
2025 MAP Growth Norms Technical Manual 2025¶
2025 MAP Growth Norms Technical Manual. (2025). HMH Education Company / NWEA. https://www.nwea.org/research/publication/2025-map-growth-norms-technical-manual/
q2 · i? · associational · r3
Section 4.1.4 reports relative-fit comparison of three candidate models (quadratic compound polynomial, linear compound polynomial, three-piece piecewise) estimated with Bayesian inference across 90 conditions; the printed result is that "64%ofthestudent-level3-piecepiecewisemodelsshowedthelowest deviancevaluesamongthethreemodelcandidates". Tables 4.1 and 4.2 report ELPD, LOOIC, and WAIC values.
"Out of the 90 conditions (45 grade-subject combinations for both student-level and school-leveldata),64%ofthestudent-level3-piecepiecewisemodelsshowedthelowest deviancevaluesamongthethreemodelcandidates,while78%oftheschool-level3-piece piecewise models produced the lowest deviance values among the three models"
Discussion¶
Related Claims¶
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- The CP model fits seasonal achievement data better than a traditional polynomial growth model on RMSE, AIC, and BIC while reducing residual autocorrelation — related
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Page metadata
| Field | Value |
|---|---|
type |
claim |
id |
piecewise-model-lowest-deviance-majority-conditions-map-norms |
title |
Across 90 grade-subject-level conditions, the three-piece piecewise model showed the lowest deviance for 64% of student-level and 78% of school-level models, outperforming both compound polynomial candidates |
description |
Across 90 grade-subject-level conditions, the three-piece piecewise model showed the lowest deviance for 64% of student-level and 78% of school-level models, outperforming both compound polynomial candidates |
status |
review |
evidence_strength |
moderate |
newest_evidence |
2025 |
source_checked |
2026-10-09 |
generated |
by process:wiki-ingest on 2026-10-08 |
trust |
unverified — no one has confirmed this page's content |
sources |
1 — 2025-map-growth-norms-technical-manual-2025 |
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