The purpose of this comparative study was to compare academic achievement and student motivation under teacher-centered and student-centered instructional methods in science grade eight at Triamudomsuksa Pattanakarn School, a government school located in Bangkok, Thailand. A total of 59 students took part in this study over a period of seven weeks. The research involved six objectives. Objectives 1 and 2 were to determine student motivation under teacher-centered and student-centered instructional methods. Objectives 3 and 4 were to determine ...