Rescoring with new item parameters changed average ability estimates negligibly, with new and original scores correlated above 0.99¶
Claim · All claims
Evidence · 1 study · designr2·q2
Currency · newest study 2022 · checked against its sources 2026-10-20 (automated, 1 of 1 entry) · not reviewed by a person · overdue for a recheck since 2025: 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? The average ability estimate difference across subjects and terms was at most 0.03 logit (0.3 RIT), while the largest individual test-level differences were 0.22–0.33 logit, and new and original ability estimates correlated above 0.99. → He 2022
Evidence¶
He 2022¶
He, W. (2022). MAP Growth item parameter drift study. NWEA Research Report. https://www.nwea.org/research/publication/map-growth-item-parameter-drift-study/
q2 · i? · design · r2
Rescoring analysis: up to 3,000 test events were randomly selected in each subject and term (Table 3.3 shows 2,476–3,000 per cell) from Fall 2011 to Spring 2013 and rescored using the operational ability estimate procedure with new item difficulty estimates. The report views the average magnitudes as negligible given the 1-point RIT reporting increment.
"The average ability estimate differences for all subjects and terms is quite small, with the largest magnitude being 0.03 logit (i.e., 0.3 RIT) observed for the Spring 2013 math tests."
Discussion¶
Related Claims¶
- Average drift in MAP Growth item difficulty estimates is negligible across subjects, with original-new correlations above 0.99 — related
- Students encountered substantial numbers of items with changed parameter estimates, averaging 11–38% of test length by subject — related
- Both item-level and test-level analyses indicate the MAP Growth measurement scales are remaining stable — a broader claim this one bears on
- Point measure correlations were unchanged by the difficulty adjustment because the new person ability estimates are linear transformations of the old ones — related
- Old (English-borrowed) and newly calibrated Spanish item RITs differ negligibly, with correlations of 0.98 and no statistically significant paired t-test differences — related
- Including or excluding calibration status 10 items in scoring has a negligible impact on Spanish student RIT scores for monolingual and bilingual students — related
- Adding collateral information has little effect on ability and item parameter estimates but more effect on speed parameter estimates — related
- Outlier rates in Spanish item calibration are extremely low, which the authors take as evidence of very high calibration quality — related
Page metadata
| Field | Value |
|---|---|
type |
claim |
id |
drift-impact-ability-estimates-negligible |
title |
Rescoring with new item parameters changed average ability estimates negligibly, with new and original scores correlated above 0.99 |
description |
Rescoring with new item parameters changed average ability estimates negligibly, with new and original scores correlated above 0.99 |
status |
review |
evidence_strength |
moderate |
newest_evidence |
2022 |
source_checked |
2026-10-20 |
recheck_by |
2025 |
generated |
by process:wiki-ingest on 2026-10-08 |
trust |
unverified — no one has confirmed this page's content |
sources |
1 — he-2022 |
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