Proportions of rare words and decontextualized utterances in parent input increase linearly from 18 to 42 months¶
Claim · All claims
Evidence · 1 study · associationalr2·q2
Currency · newest study 2012 · not yet checked against its sources · not reviewed by a person · overdue for a recheck since 2017: baselines and conditions change
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 proportion of parent word types that were rare and the proportion of utterances that were decontextualized both increased significantly from 18 to 42 months. → Rowe Meredith L 2012
Evidence¶
Rowe Meredith L 2012¶
Rowe Meredith L. (2012). A longitudinal investigation of the role of quantity and quality of child-directed speech in vocabulary development. Child development. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3440540/
q2 · i? · associational · r2
Linear contrast analysis of input proportions across 50 dyads. "a significant linear increase in the proportion of word types that were rare (t(49) = 5.36, p < 0.001)" and decontextualized utterances (t(49) = 5.63, p < 0.001).
"Linear contrasts (Furr, 2008; Rosenthal, Rosnow & Rubin, 2000) revealed a significant linear increase in the proportion of word types that were rare (t(49) = 5.36, p < 0.001) and the proportion of utterances that were decontextualized (t(49) = 5.63, p < 0.001) from 18 to 42 months."
Discussion¶
Related Claims¶
- Parent explanations at 42 months are marginally related to child PPVT at 54 months with controls — related
- Parent education relates to input quantity and quality but not to narrative utterances — related
- Parental language input differs in quantity and quality across SES groups and relates to children's vocabulary, grammar, and processing development — related
- Parent rare word use at 30 months predicts child PPVT at 42 months with quantity, SES, and prior vocabulary controlled — related
- Parent vocabulary diversity at 30 months predicts child PPVT at 42 months with quantity, SES, and prior vocabulary controlled — related
- Parent narrative utterances at 42 months predict child PPVT at 54 months with quantity, SES, and prior vocabulary controlled — related
Page metadata
| Field | Value |
|---|---|
type |
claim |
id |
proportions-rare-decontextualized-increase-over-time |
title |
Proportions of rare words and decontextualized utterances in parent input increase linearly from 18 to 42 months |
description |
Proportions of rare words and decontextualized utterances in parent input increase linearly from 18 to 42 months |
status |
review |
evidence_strength |
moderate |
newest_evidence |
2012 |
recheck_by |
2017 |
generated |
by process:wiki-ingest on 2026-10-17 |
trust |
unverified — no one has confirmed this page's content |
sources |
1 — rowe-meredith-l-2012 |
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