Fractions knowledge is a critical domain-specific predictor of mathematics achievement in later grades¶
Claim · All claims
Evidence · 1 study · associationalr2·q3
Currency · newest study 2017 · checked against its sources 2026-10-24 (automated, 1 of 1 entry) · 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.
q3 i? In 8th grade, the effect of 6th-grade fractions comparison on mathematics achievement (β = .206, p = .002) was at least as large as the central executive effect (β = .18, p = .007); in grades 6 and 7 the fractions effect was significant but smaller than the central executive's (β = .150 and .178 against .252 and .248). → Geary David C. 2017
Evidence¶
Geary David C. 2017¶
Geary David C., Nicholas Alan, Li Yaoran, Sun Jianguo. (2017). Developmental Change in the Influence of Domain-General Abilities and Domain-Specific Knowledge on Mathematics Achievement: An Eight-Year Longitudinal Study. Journal of Educational Psychology. https://doi.org/10.1037/edu0000159
q3 · i? · associational · r2
Model 5 of the longitudinal functional data analysis (n = 167) added the 6th-grade fractions comparison measure and estimated effects for grades 6 to 8 only. The fractions effect rose from β = .150 (p = .021) in 6th grade to .178 (p = .002) in 7th and .206 (p = .002) in 8th, while the central executive effect fell from .252 and .248 to .180 (p = .007). Only in 8th grade was the fractions effect at least as large as the central executive's. The data are correlational and, as the authors note, do not support strong causal inferences.
"the individual effect for fractions comparison (β = .206, p<.002) is at least as important as that of the central executive (β = .18, p<.007)."
Discussion¶
Learner Variables¶
- Prior Knowledge — predictor: learners who differ on it differ in outcomes
- Proportional Reasoning — predictor: learners who differ on it differ in outcomes
Related Claims¶
- The central executive component of working memory is the most important domain-general predictor of later-grade mathematics achievement — related
- Domain-general abilities are more important than domain-specific knowledge for mathematics learning in early grades, but the two are equally important in later grades — related
- Fraction magnitude understanding, measured by number line estimation, predicts general mathematics achievement beyond fraction arithmetic skill in 5 of 6 Belgian, Chinese and U.S. grade samples, though not among Chinese 8th graders — related
- The relation between fraction magnitude understanding and mathematics achievement is a general cognitive characteristic, not attributable to specifics of the U.S. educational system, though instruction quality may strengthen or weaken it — related
- The overall magnitude of domain-general effects on subsequent mathematics achievement remains constant across grades 2 to 8 — related
- Previous domain knowledge accounts for most of the variance in later achievement, considerably reducing the predictive impact of IQ and WM — a broader claim this one bears on
Page metadata
| Field | Value |
|---|---|
type |
claim |
id |
fractions-knowledge-predicts-later-achievement |
title |
Fractions knowledge is a critical domain-specific predictor of mathematics achievement in later grades |
description |
Fractions knowledge is a critical domain-specific predictor of mathematics achievement in later grades |
status |
review |
evidence_strength |
moderate |
newest_evidence |
2017 |
source_checked |
2026-10-24 |
generated |
by process:wiki-ingest on 2026-10-24 |
trust |
unverified — no one has confirmed this page's content |
sources |
1 — geary-david-c-2017 |
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