At least 90% of reading and science items and about 80% of math items show difficulty differences within 0.3 logits between on-grade and all-grade calibration¶
Claim · All claims
Evidence · 1 study · associationalr2·q2
Currency · newest study 2021 · not yet checked against its sources · not reviewed by a person · overdue for a recheck since 2024: 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? Using the 0.3 logit difference criterion, at least 90% of reading and science items and about 80% of math items in most grades show comparable on-grade and original difficulty estimates. → Wei He 2021
Evidence¶
Wei He 2021¶
Wei He, NWEA Psychometric Solutions. (2021). An Investigation of Item Parameter Invariance Using Focused Calibration Samples for MAP Growth. NWEA. https://www.nwea.org/research/publication/an-investigation-of-item-parameter-invariance-using-focused-calibration-samples-for-map-growth/
q2 · i? · associational · r2
Study 1 categorized items by the size of the on-grade minus all-grade difficulty difference (Figure 3.2). The report states "at least 90% of reading and science items had differences within 0.3 logits for almost all grades" and about 80% of math items. Box plots (Figure 3.1) show a few math and reading items exceeded 1 logit.
"at least 90% of reading and science items had differences within 0.3 logits for almost all grades. Math tended to see fewer items, about 80% of items for most grades, with differences within 0.3 logits."
Discussion¶
Related Claims¶
- Average on-grade and all-grade item difficulty estimates differ by less than 0.1 logit for MAP Growth items — related
- For items aligned to multiple target grades, difficulty estimates from different on-grade calibration samples differ negligibly, at most 0.1 logit on average — related
- Calibration sample size differences did not affect the size of on-grade versus all-grade item difficulty estimate differences — related
- Item difficulty estimates from target-plus-adjacent-grade samples generally differ from original estimates about as much as on-grade estimates do, with mean differences within 0.11 logit — related
Page metadata
| Field | Value |
|---|---|
type |
claim |
id |
map-growth-most-items-within-03-logit-ongrade-calibration |
title |
At least 90% of reading and science items and about 80% of math items show difficulty differences within 0.3 logits between on-grade and all-grade calibration |
description |
At least 90% of reading and science items and about 80% of math items show difficulty differences within 0.3 logits between on-grade and all-grade calibration |
status |
review |
evidence_strength |
moderate |
newest_evidence |
2021 |
recheck_by |
2024 |
generated |
by process:wiki-ingest on 2026-10-08 |
trust |
unverified — no one has confirmed this page's content |
sources |
1 — wei-he-2021 |
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