Claims

Adding a quadratic achievement term leaves the negative contextual-mean effect essentially unchanged

Claim · All claims
Evidence · 1 study · associational r2 · q2
Currency · newest study 2026 · not yet checked against its sources · not reviewed by a person

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? Modest nonlinearity in the achievement–self-concept relation exists, but including L1² does not materially alter the negative class-average effect. → Herbert W. Marsh 2026

Evidence

Herbert W. Marsh 2026

Herbert W. Marsh. (2026). Four Decades After the Big-Fish–Little-Pond Effect: Critical Boundary Tests and Integrative Models of Mean-Context, Ordinal-Standing, and Distributional-Scaling in 46 Countries. Educational Psychology Review. https://doi.org/10.1007/s10648-026-10200-0

q2 · i? · associational · r2

Multilevel Model 3 in the same TIMSS 2019 sample added a quadratic achievement term, confirming "modest nonlinearity in the L1–MSC relation (L1² = 0.104, SE = 0.002)" while the contextual effect stayed essentially unchanged (L2 = − 0.660, SE = 0.006).

"Model 3 (Table 1) added a quadratic term for individual achievement and confirmed modest nonlinearity in the L1–MSC relation (L1² = 0.104, SE = 0.002; L1 = 0.577, SE = 0.003). Crucially, however, inclusion of the quadratic term left the contextual effect essentially unchanged (L2 = − 0.660, SE = 0.006, compared with − 0.633 in Model 2)."

Discussion

Learner Variables

Page metadata
Field Value
type claim
id curvature-adjustment-does-not-eliminate-bflpe
title Adding a quadratic achievement term leaves the negative contextual-mean effect essentially unchanged
description Adding a quadratic achievement term leaves the negative contextual-mean effect essentially unchanged
status review
evidence_strength moderate
newest_evidence 2026
generated by process:wiki-ingest on 2026-10-21
trust unverified — no one has confirmed this page's content
sources 1 — herbert-w-marsh-2026

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