Abstract
In developing nations across the Asia-Pacific region, English language proficiency is increasingly tied to economic mobility and regional integration. However, rural students face persistent educational disparities due to a lack of qualified teachers and learning resources. This study presents a randomized controlled trial (RCT) evaluating the efficacy of a Mobile-Assisted Language Learning (MALL) application designed to enhance English literacy among grade-7 students in rural Cambodia. Over a 12-week intervention period, 184 students from four rural schools in Kampong Speu province were randomly assigned to either an experimental group (using an offline-capable MALL application on smartphones for 45 minutes daily) or a control group (utilizing standard paper-based self-study materials). Pre- and post-test assessments measured English vocabulary, pronunciation, and reading comprehension. The results revealed that the treatment group achieved significantly higher gains in vocabulary acquisition (d = 0.68, p < 0.001) and pronunciation accuracy (d = 0.54, p < 0.01) compared to the control group. Reading comprehension improvements were positive but modest (d = 0.22, p = 0.12). Moderation analysis indicated that regular parental involvement and consistent smartphone access significantly amplified the application's pedagogical benefits. These findings suggest that offline-capable MALL interventions offer a scalable, cost-effective pathway to mitigate rural-urban educational divides in resource-constrained environments.
