LLLI exposure in preschool produced no statistically significant main effects on kindergarten expressive vocabulary, decoding, or passage comprehension¶

Claim · All claims
Evidence · 1 study · causal r2 · q3
Currency · newest study 2016 · checked against its sources 2026-11-01 (automated, 1 of 1 entry) · not reviewed by a person

Subclaims¶

q3 i? Children whose preschool teachers implemented LLLI did not significantly outperform business-as-usual children on any of the three kindergarten outcomes (Table 4: p = .15 expressive vocabulary, .23 letter-word identification, .61 passage comprehension; the text summarises these as "ps > .20"), though all raw differences favored the treatment group (descriptive d = 0.02, 0.19 and 0.02). → Johanson 2016

Evidence¶

Johanson 2016¶

Johanson, M., Justice, L. M., & Logan, J. (2016). Kindergarten Impacts of a Preschool Language-Focused Intervention. Applied Developmental Science, 20(2), 94-107. https://doi.org/10.1080/10888691.2015.1074050

q3 · i? · causal · r2

HLM analysis of the RCT follow-up (247 children nested in 49 classrooms) tested treatment differences on three kindergarten outcomes controlling for fall preschool language composite; the article reports the main effects were in the desired direction but "none of the effects were found to be statisti- cally significant ( ps > .20)." Its Table 4 prints the treatment p values as .150 (expressive vocabulary), .230 (letter-word identification) and .61 (passage comprehension), so the expressive-vocabulary p is below the .20 the text states, though still nonsignificant. Table 3 gives descriptive effect sizes of d = 0.02, 0.19 and 0.02. Nonsignificance here does not show the intervention had no effect.

"However, none of the effects were found to be statisti- cally significant ( ps > .20)."

Discussion¶

Learner Variables¶

• Communication Skills — outcome: instruction changes it
• Oral Language — outcome: instruction changes it
• Vocabulary — outcome: instruction changes it

Related Claims¶

• The kindergarten benefits of the LLLI intervention on decoding and reading comprehension were conditional on children's initial preschool language skill, favoring children with high language skill — related
• Initial preschool language skill did not moderate the LLLI intervention effect on kindergarten expressive vocabulary — related