Formative assessment, as a strategy used to improve student learning, encounters several obstacles in its implementation. This study explores changes in teachers' views and practices as they are introduced to formative assessment in a high stakes testing and limited resource environment. The study examines the extent to which teachers use the technique of formative assessment to engage students in authentic learning even while not sacrificing high test scores on summative assessments. A case study methodology was employed to address the research topic. Science teachers in the West African country of Cameroon were engaged in a process of lesson planning and implementation to collaboratively build lessons with large amounts of formative assessment. Qualitative data from written surveys, group discussions, classroom and workshop observations, and from teacher reflections reveal the extent to which lesson fidelity is preserved from views to planning to implementation. The findings revealed that though the teachers possess knowledge of a variety of assessment methods they do not systematically use these methods to collect information which could help in improving student learning. Oral questioning remained the dominant method of student assessment. The study also showed that the teachers made minimal to big changes depending on the particular aspect of formative assessment being considered. For aspects which needed just behavioral adaptations, the changes were significant but for those which needed acquisition of more pedagogic knowledge and skills the changes were minimal. In terms of constraints in the practice of formative assessment, the teachers cited large class size and lack of teaching materials as common ones. When provided with the opportunity to acquire teaching materials, however, they did not effectively utilize the opportunity. The study revealed a need for the acquisition of inquiry skills by the teachers which can serve as a platform for the implementation of formative assessment. Another implication of the findings is for teacher professional development to be on-going and classroom-based providing opportunities for teachers to experience and try new teaching methods. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]