Abstract: Conventional, teacher centered teaching is not sufficient in science, technology, engineering and mathematics education at the present time. Therefore, new teaching strategies and methods have consistently been developed by the educators. One of the new developed teaching methods is peer instruction. Peer instruction is interactive teaching method. Peer instruction is quite easy and practical to implement therefore peer instruction might be adapted to different disciplines of science, social sciences, and engineering. The effectiveness of peer instruction and conventional, teacher centered teaching on students’ conceptual learning were compared by calculating fractional gains with the help of some standardized tests including "Force Concept Inventory-FCI, Force and Motion Conceptual Evaluation-FMCE, Conceptual Survey of Electricity and Magnetism, CSEM" in this study. The normalized gains of studies performed and recorded between 1990 and 2016 were evaluated and discussed. When the examined studies were generally interpreted, students’ conceptual understanding performance instructed with peer instruction was higher than students’ conceptual learning performance instructed with conventional, teacher centered teaching.