Empirical Analysis of Blended Learning Effectiveness on Academic Achievement in Nigerian Federal Universities: Evidence from Rivers State

This study empirically analyses the effectiveness of blended learning on students' academic achievement in federal universities in Rivers State, South South Nigeria. Blended learning, which combines face-to-face instruction with online components, has been widely advocated as a strategy for improving higher education quality in Nigeria, yet rigorous empirical evidence from the Rivers State context remains sparse. The study employed a mixed-methods sequential explanatory design. In the quantitative phase, a quasi-experiment compared the academic achievement of 180 undergraduate students in blended and conventional learning conditions across two courses over one semester. In the qualitative phase, semi-structured interviews with 20 participants explored the mechanisms behind observed outcomes. Analysis of covariance revealed a significant achievement advantage for students in blended learning conditions, with effect sizes indicating practical significance. Qualitative findings attribute this advantage to increased self-regulation opportunities and flexible access to lecture recordings. Moderating analysis shows that students with prior technology experience benefit most from blended formats. The study contributes empirical data to the growing literature on blended learning in sub-Saharan Africa and recommends that federal universities in Rivers State formalise blended learning policies supported by staff training and student orientation frameworks. Keywords: blended learning, academic achievement, federal universities, Rivers State, mixed methods