The secondary school education system in Tanzania is undergoing significant reforms aimed at improving educational outcomes. A DID analysis was employed to measure the effect of the reform interventions, with pre- and post-intervention data collected from a sample of secondary schools across Tanzania. The results indicated an adoption rate of 75% among participating schools, with a statistically significant increase in student performance scores by 20% post-reform (95% CI: 10%, 30%). The difference-in-differences model provided robust evidence for the effectiveness of the educational reforms. Further studies should explore the sustainability and scalability of these reform measures in different regions of Tanzania. Secondary schools, adoption rates, difference-in-differences, education reforms, student performance The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.