Four years after the LEAP trial, LEAP graduates scored higher than comparison children on all measures, but only cognitive (Leiter) and teacher-rated prosocial skills differences were statistically significant¶

Claim · All claims
Evidence · 1 study (3 entries) · causal r2 · q3 · i2 medium
Currency · newest study 2017 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q3 i2 Leiter Brief IQ mean differences favoring LEAP graduates (76 vs 93) were statistically significant with d = .42. → Strain 2017 q3 i2 SSRS prosocial differences favoring LEAP participants (31 vs 39.8) were statistically significant with d = .52. → Strain 2017 (2) q3 i? Kaufman (86 vs 95), TOLD (81 vs 88), and Vineland (94 vs 98) differences favoring LEAP graduates were not statistically significant. → Strain 2017 (3)

Evidence¶

Strain 2017¶

Phillip S. Strain. (2017). Four-Year Follow-Up of Children in the LEAP Randomized Trial: Some Planned and Accidental Findings. Topics in Early Childhood Special Education, 37(2), 121–126. https://doi.org/10.1177/0271121417711531

q3 · i2 · causal · r2

Follow-up assessment of original RCT participants in both study arms, with assessors blind to prior study group membership and a 32% attrition rate evenly divided between arms. The blind assessment found Leiter means of 76 versus 93, "statistically significant, t(177) = 2.12, p = .05" with d = .42.

"Leiter mean differences favoring LEAP graduates of 76 versus 93 were statistically significant, t(177) = 2.12, p = .05. Using Cohen’s d, effect size for this finding was .42."

Strain 2017 (2)¶

Phillip S. Strain. (2017). Four-Year Follow-Up of Children in the LEAP Randomized Trial: Some Planned and Accidental Findings. Topics in Early Childhood Special Education, 37(2), 121–126. https://doi.org/10.1177/0271121417711531

q3 · i2 · causal · r2

Teacher-rated SSRS prosocial measure at 4 years post, where higher scores represent greater perceived social skills. The follow-up testing found means of 31 versus 39.8 favoring LEAP participants, "statistically significant, t(180) = 2.99, p < .01" with d = .52.

"Differences favoring LEAP participants (31 vs. 39.8) were statistically significant, t(180) = 2.99, p < .01. Again, using Cohen’s d, the effect size for this finding was .52."

Strain 2017 (3)¶

Phillip S. Strain. (2017). Four-Year Follow-Up of Children in the LEAP Randomized Trial: Some Planned and Accidental Findings. Topics in Early Childhood Special Education, 37(2), 121–126. https://doi.org/10.1177/0271121417711531

q3 · i? · causal · r2

The same blind follow-up battery found Kaufman means of 86 versus 95 favoring LEAP graduates that were "not statistically significant using a two-tailed t test"; the article likewise reports non-significant TOLD (81 vs 88) and Vineland (94 vs 98) differences. Equivalence was not tested.

"Mean group differences on the Kaufman of 86 versus 95 in favor of LEAP graduates were not statistically significant using a two-tailed t test."

Discussion¶

Related Claims¶

• Among CARS-matched pairs, children placed in inclusive kindergartens significantly outperformed peers in segregated settings on achievement, language, cognition, adaptive behavior, autism symptoms, and prosocial skills four years later — related