Person:

Kim, James S.

This mixed-methods study explores the relationship between early elementary students’ domainspecific vocabulary knowledge and their ability to comprehend grade-level reading passages on unfamiliar science topics. Specifically, this study used (a) structural equation modeling (SEM) to examine the extent to which students’ networks of domain-specific vocabulary knowledge in Grades 1 and 2 mediated the effects of a Tier 1 content-based literacy intervention on domainspecific reading comprehension scores in Grade 2 (N = 2,156); and (b) quantitative survey and qualitative interview data from teachers (N = 48) to surface new themes about teacher vocabulary instruction that might suggest potential explanations for the SEM findings. SEM analysis revealed that students’ domain-specific vocabulary knowledge in first and second grade explained 69% of the treatment effect on a domain-specific reading comprehension outcome. Results from the quantitative survey also indicated that treatment group teachers reported providing more incidental exposures to vocabulary than control teachers (Effect Size [ES] = .54) and qualitative analyses revealed that teachers with high incidental exposures tended to provide expanded opportunities for their students to engage with words and to connect words to topics. Findings from this mixed-method study paint a more complete picture of (a) the important role domain-specific vocabulary knowledge plays in facilitating reading comprehension transfer in the domain of science, and (b) what teachers do during vocabulary instruction to promote transfer in domain-specific reading comprehension.

This experimental study aimed to replicate and extend a previous efficacy study of an elementary grade content literacy intervention that demonstrated positive effects on students’ vocabulary knowledge depth, argumentative writing, and reading comprehension. Using a cluster (school) randomized trial design, this replication experiment was conducted with 5,494 first- and second- grade students in 30 elementary schools in an urban school district located in the southeastern United States. Teachers implemented thematic lessons (20 lessons) that provided an intellectual framework for helping students acquire networks of related vocabulary knowledge while learning science and social studies content. Teachers integrated thematic lessons, concept mapping, and interactive read-alouds of conceptually related informational texts to enable their students to build networks of vocabulary knowledge and to transfer this knowledge to argumentative writing and collaborative research activities. Confirmatory analyses replicated positive findings on science vocabulary knowledge depth (ES = 0.50) and argumentative writing (ES = 0.24) and also extended positive findings to social studies vocabulary knowledge depth (ES = 0.56) and argumentative writing (ES = 0.44). Positive and statistically significant findings were not replicated on domain-general reading comprehension outcomes. Exploratory analyses indicated that students’ vocabulary knowledge depth partially mediated the impact of content literacy instruction on domain-specific argumentative writing outcomes.

This exploratory follow-up study to a randomized controlled trial examined (a) the differential impact of classroom-based (Tier 1) content literacy intervention on reading and argumentative writing outcomes among Grades 1 and 2 English learners (ELs; n = 1,236) and their Englishproficient peers (EPs; n = 4,161) and (b) the mechanisms determining how the intervention yielded effects on ELs. The study was conducted across 30 elementary schools in an urban U.S. school district. The 10-week intervention, comprised of 20 lessons in science and social studies thematic units, was delivered by classroom teachers. The core components were designed to build students’ content and vocabulary knowledge through informational texts and concept mapping and to transfer their schema to argumentative writing and research collaboration. Results show that while the intervention did not significantly improve reading proficiency (effect size [ES] = .01 for ELs and ES = -.02 for EPs) and basic literacy skills (ES = .04 for ELs and ES = -.02 for EPs), it significantly bolstered argumentative writing in science (ES = .25 for ELs and ES = .24 for EPs) and social studies (ES = .42 for ELs and ES = .44 for EPs). The treatment effect on reading proficiency among ELs was fully mediated by their improved domain-specific vocabulary knowledge and English oral proficiency. A significant indirect effect on social studies argumentative writing through domain-specific vocabulary knowledge was also evident. These findings corroborate the effectiveness of the content literacy intervention, providing insights into for whom and how the intervention was effective.