Teachers need to project into the future as regards the needs of the students of whom responsibility has been given to take care of at present.This they do through the use of such tools in education such as testing. Over the past two decades, nations have relied on testing of students as the major indicator of school effectiveness. Thus, assessments of students' learning through tests have become more and more common and the results from these tests are used to make significant educational decisions about schools, policies and/or programmes, teachers, administrators and students. The uses and misuses of the results from these tests make these tests high-stakes, especially, when the results of the tests have perceived or real consequences for students, teachers or schools. This volume brings to fore an empirical evidence on the effect of high-stakes testing on curriculum implementation and instruction among mathematics, science and English teachers in senior high schools. This work is especially important for teachers, students and professionals in educational assessment, instructional psychology, guidance and counseling, pre-service teachers and educational administrators.