Levelling Up Writing: Investigating Duolingo’s Gamification Effect on EFL Students’ Writing Skills

Duolingo has become one of the most widely used gamification apps for learning English, mostly for vocabulary and grammar. However, there is limited research on its effectiveness in enhancing writing skills. This study aimed to investigate the effect of Duolingo on junior high school students' learning English as a Foreign Language (EFL) writing skills, focusing on the overall score and five components: content, organization, vocabulary, language use, and mechanics. The study used a quasi-experimental design, specifically the non-equivalent control group, involving 41 eighth-grade students in experimental and control groups. Both groups were assigned writing tests as a pre-test and a post-test. The experimental group received an intervention using Duolingo outside the classroom for eight weeks as a supplementary tool, while the control group only received regular English classes. The statistical analysis using the independent t-test and ANCOVA revealed a significant improvement in writing skills in the experimental group (p < .05). It also showed an improvement in all writing components, especially content and organization. The partial eta squared value indicated a large effect of Duolingo (η²p = .878). These findings suggest that Duolingo has the potential to serve as a supplementary tool for improving writing skills in language learning.