A quasi-experimental field trial conducted by Proctor and colleagues, which was published in Reading Research Quarterly, examined the effects of a language-based reading intervention, called CLAVES, among bilingual students in Grades 4 and 5. The framework of CLAVES consisted of language components, language functions, discussion, and reading comprehension, which integrated ELA and social studies into three thematic units. Each unit had three instructional cycles, focusing on text-based language and comprehension (Cycle 1 & 2) and writing (Cycle 3).
239 bilingual students (Portuguese-English and Spanish-English) from 8 schools in the Northeast and the Mid-Atlantic regions of the US were assigned to the intervention group (n=119) and the control group (n=120). The participating teachers (n=22) were responsible for both intervention and control group instruction.
Results showed significant positive effects of the intervention on both reading comprehension (ES=+0.17) and academic language (ES=+0.25). No moderation effects were found by pre-intervention language proficiency on the outcomes.