Declining science enrolment, with the greatest decline in physics, is well documented and has generated concern surrounding students' future abilities to function in an increasingly scientific and technology-focused society. This book is a multiphase qualitative phenomenological research study guided by the following questions: (a) Why do students select or reject physics courses? (b) What role does physics identity play in student course selection? (c) What other factors, extrinsic or intrinsic, affect their choices to pursue physics? To answer these questions, data from questionnaires, interviews, focus groups and student drawings are used. The results from this study contribute to the ongoing dialogue about ways to engage students in physics. This book will be especially useful for curriculum designers, physics educators, and physics education researchers.