The aim of this study was to investigate the reasoning behind the policy change. Zanzibar introduced the new education policy in 2006. This study is within education policy planning specifically in the area of language of instruction (LoI) in teaching science and mathematics in public primary schools. The study focuses on the process of policy formulation. The empirical research was guided by the following questions: what were the main reasons that prompted policy makers to change the LoI in teaching science and mathematics from grade five onward? What were the sources of information used by the policy makers to change the LoI? Were there any pedagogical limitations associated with the use of Kiswahili as the LoI? How education stakeholders at community level were involved in the decision to introduce changes of the LoI?
Data were collected through interviews and document reviews. The study involved 85 participantswho were drawn from national to community level.The study was conducted in Zanzibar (Unguja and Pemba). The main findings: the main reasons to change the LoI were to improve the quality of education, to improve students’ English language proficiency, responses to globalization, privatization and liberalization forces as well as international organizations influence. The information used by policy makers to change the LoI was obtained from researches, program reviews and views from group discussion. There were no pedagogical limitations associated with the use of Kiswahili as the LoI. Community participation in the process of policy formulation was limited.
From these findings I concluded that for quality improvement Kiswahili should continue to be the LoI and English should be taught as a foreign language. Efforts should be made to improve teaching and learning environment in public primary schools. This study is very useful since it provides information which can be used by educational administrators, planners, supervisors, policy makers as well as teachers for future planning of education policies by considering socio-economic and linguistics context of Zanzibar. The findings also can help to improve community participation in the formulation of education policies.