Impact of a content-rich English language arts program on kindergarten students' language and knowledge

Impact of a content-rich English language arts program on kindergarten students' language and knowledge

First Author: Sonia Cabell -- Florida State University
Additional authors/chairs: 
James Kim; Thomas White; HyeJin Hwang; Charles Gale
Keywords: Oral Language, Knowledge Building, Academic Language, RCT, science
Abstract / Summary: 

Purpose: This presentation reports on two randomized controlled trials examining the effects of the widely used Core Knowledge Language Arts: Knowledge Strand (CKLA) curriculum on kindergarteners’ vocabulary, listening comprehension, and knowledge.

Method: In each of two studies, schools were randomly assigned within a single urban U.S. district to either the treatment (n = 11, 12) or BAU control condition (n = 12, 12). Kindergarten teachers in treatment schools implemented CKLA for one semester, focusing on science and social studies topics. Kindergarten teachers in control schools implemented BAU practices, which included some content integration. Students (n=1,194) were individually tested in the fall (prior to randomization) and spring on a battery of researcher-created and standardized assessments of oral language and knowledge.

Results: Results of multilevel modeling indicated that children in the treatment condition learned the words taught (ES = 0.46, 0.65) and content knowledge taught (ES = 0.34 – 1.33) by the program. To increase precision across effect size estimates, we meta-analyzed the results across the studies. Notably, the effect sizes for standardized measures of expressive vocabulary (ES = .085; WJ-III Picture Vocabulary) and science knowledge (ES = 0.116; WJ-III Science) were statistically significant. There were no discernable main effects on standardized measures of listening comprehension or social studies knowledge.

Conclusion: To date, there have only been a handful of experimental studies examining a content-rich kindergarten ELA curriculum, but none of them have examined widely used curricula. Thus, our work makes an much-needed and meaningful contribution to the scarce literature in this area.