World of Words has positive effects on the language outcome domain for prekindergarten children, with an average effect size of 0.43 across four studies¶

Claim · All claims
Evidence · 1 study · quant-synthesis r? · q3 · i2 medium
Currency · newest study 2023 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q3 i2 Across four studies meeting WWC standards, the average effect of World of Words on language outcomes was statistically significant and positive (effect size 0.43, improvement index +16, p < 0.01). → wwc-summary

Evidence¶

wwc-summary¶

What Works Clearinghouse, Institute of Education Sciences, U.S. Department of Education. (2023, August). World of Words. https://whatworks.ed.gov

q3 · i2 · quant-synthesis · r?

WWC systematic review synthesizing four studies (two cluster RCTs without reservations, two with reservations) totaling 992 children in Head Start and state-funded preschool sites, using a weighted average across the language domain. The summary effect size was 0.43, with an improvement index of +16 and p < 0.01 per Table 4.

"World of Words had positive effects on language development because the average effect across all outcomes and studies was statistically significant and positive for measures in the language domain."

Discussion¶

Learner Variables¶

• Vocabulary — outcome: instruction changes it

Related Claims¶

• World of Words produced a statistically significant medium effect on expressive vocabulary (Expressive One-Word Picture Vocabulary Test, 4th Edition; effect size 0.43) in a scaled-up 12-site study — a narrower finding that bears on this claim
• World of Words produced a large, statistically significant effect on taught-word sorting performance (effect size 0.94) in a two-site Head Start study — a narrower finding that bears on this claim
• World of Words produced a statistically significant medium-to-large effect on a researcher-developed vocabulary inductive reasoning test (effect size 0.66) — a narrower finding that bears on this claim