The Role of Formative Assessment in Enhancing Biology Learning: Evidence from Secondary Schools in Dar es Salaam City Council, Tanzania

Abstract This study investigates the role of formative assessment in enhancing student learning outcomes in Biology, focusing on selected secondary schools in Dar es Salaam City Council, Tanzania. Drawing on Constructivist Theory and the self-regulated learning framework, the study employed a mixed-methods approach with a descriptive design. Data were collected from 156 participants, including teachers, students, and head teachers, using structured questionnaires, interviews, and classroom observations. Regression analysis revealed that teacher-student oral discussions were a significant predictor of student performance (β=0.67,p<0.01\beta = 0.67, p < 0.01β=0.67,p<0.01), demonstrating their critical role in fostering conceptual understanding and critical thinking. Teacher observations and group projects also emerged as effective formative practices, enabling the identification of learning gaps and fostering collaborative problem-solving skills. Despite these benefits, the study identified systemic barriers, including large class sizes, inadequate teacher training, and resource constraints, which hinder the widespread implementation of formative assessment. These findings emphasize the need for systemic reforms, including professional development for teachers, curriculum integration of formative practices, and resource allocation to support interactive and feedback-driven learning. The study concludes that formative assessment significantly enhances Biology learning outcomes and provides actionable recommendations to address the structural challenges limiting its adoption in Tanzanian secondary schools.