Time to Transfer: Long-Term Effects of a Sustained and Spiraled Content Literacy Intervention in the Elementary Grades

This peer-reviewed study reports findings from a longitudinal randomized controlled trial examining the long-term effects of a sustained, spiraled content literacy intervention—the Model of Reading Engagement (MORE)—implemented from Grades 1 through 3. The intervention is designed to systematically build students’ background knowledge, academic vocabulary networks, and schema awareness through thematically connected science instruction and wide reading over multiple years. Tracking 2,870 students across 30 elementary schools, the study finds that students who participated in the full spiral curriculum outperformed peers on science vocabulary knowledge, Grade 3 science reading comprehension, domain-general reading comprehension, and mathematics achievement. Importantly, these effects were not short-lived: gains in reading and math were sustained 14 months later in Grade 4, demonstrating meaningful far-transfer across subjects and over time. The results provide strong evidence that sustained, knowledge-building literacy instruction can produce durable improvements in students’ academic achievement beyond reading alone, with effects comparable to or exceeding many widely used interventions.