Foundational English Literacy Outcomes Associated with Jolly Phonics Implementation in Tanzania: A Quasi-experimental Pilot Study

Abstract

Developing foundational English literacy is essential for children’s later academic success. Yet, many pupils in multilingual education systems, such as those in Tanzania, struggle to acquire the decoding skills needed for early reading. Although systematic synthetic phonics has improved early literacy in many contexts, there is limited empirical evidence regarding the effectiveness of Jolly Phonics in Tanzanian public primary schools. This study examined changes in foundational English literacy associated with the implementation of Jolly Phonics among Standard One pupils in Tanzania. The study employed a quasi-experimental pretest-posttest non-equivalent comparison-group design across 16 public primary schools in Dar es Salaam and Morogoro, comprising 12 intervention schools implementing Jolly Phonics and four comparison schools. Literacy outcomes were assessed at baseline and after a 15-week intervention using measures of letter-sound recognition, word reading, and oral vocabulary. Pupils in both groups improved over the study period; however, those receiving Jolly Phonics consistently demonstrated larger gains across all three literacy domains. Mean gains in the intervention group exceeded those in the comparison group for letter–sound recognition (11.67 vs. 6.54 points), word reading (7.89 vs. 2.94 points), and oral vocabulary (2.56 vs. 0.39 points). Nevertheless, the groups were non-equivalent at baseline, particularly in word reading, and the analyses relied on aggregated programme data. Consequently, the findings provide descriptive evidence that participation in Jolly Phonics was associated with improved foundational English literacy rather than definitive evidence of causal effects. The study highlights the potential of systematic synthetic phonics to strengthen early English literacy instruction in Tanzanian public primary schools and underscores the need for further research using more rigorous evaluation designs.