Vocabulary knowledge is integral to reading comprehension. A recent study published in the Reading Research Quarterly evaluated the effectiveness of a vocabulary intervention on English learners’ acquisition of academic vocabulary.
The intervention, called the Acquisition of Vocabulary in English, was conducted with 424 Spanish-English speaking students in second grade who were identified as English learners. In this stratified cluster randomized control trial, 22 classrooms were randomly assigned either to the intervention group (n=12) or the control group (n=10). Students in the intervention group received four 50-minute lessons weekly for 18 weeks. Teachers in the intervention group used selected books with target vocabulary and applied activities to reinforce vocabulary learning, while teachers in the control group solely read the same books with target vocabulary. The results suggest that
- The intervention was effective on English learners’ acquisition of challenging, high-utility English vocabulary. Specifically, the effect size (Cohen’s d) was +1.88 for content words (i.e., meaning-carrying words), +0.14 for connecting words (i.e., function words like because, therefore), and +0.47 for oral language.
- The study further examined whether effects differed by word characteristics, such as cognate status and abstractness designation. The findings indicated higher effect sizes for noncognates, both concrete and abstract, than cognates.
As highlighted by the authors, the study had three innovative components: focusing on both content words and connecting words, examining whether the intervention effects varied by word characteristics, and implementing activities to support oral language development in general. The findings support a promising research path for further examination of word characteristics when designing vocabulary interventions.