*39%*:**Student understanding of quantum mechanics at the beginning of graduate instruction***38%*:**Investigating student understanding of basic quantum mechanics in the context of time-dependent perturbation theory***38%*:**Exploring Student Understanding of Energy through the Quantum Mechanics Conceptual Survey***37%*:**Assessing and improving student understanding of quantum mechanics***37%*:**Improving student understanding of addition of angular momentum in quantum mechanics***36%*:**The Influence of Student Understanding of Classical Physics When Learning Quantum Mechanics***36%*:**Student Difficulties in Understanding Probability in Quantum Mechanics***34%*:**Surveying students' understanding of quantum mechanics in one spatial dimension***34%*:**Quantum Mechanics Students' Understanding of Normalization***33%*:**Improving students' understanding of quantum mechanics via the Stern–Gerlach experiment***33%*:**Investigating Student Difficulties with Time dependence of Expectation Values in Quantum Mechanics***33%*:**Testing the development of student conceptual and visualization understanding in quantum mechanics through the undergraduate career***33%*:**Surveying Students’ Understanding of Quantum Mechanics***33%*:**Improving Students' Understanding of Quantum Mechanics***33%*:**Improving students’ understanding of quantum measurement. I. Investigation of difficulties***33%*:**Student difficulties with determining expectation values in quantum mechanics***32%*:**Improving Students' Understanding of Quantum Mechanics***32%*:**Students’ Conceptual Understanding of Quantum Physics in College Level Classroom Environments***32%*:**Analogous Patterns of Student Reasoning Difficulties in Introductory Physics and Upper- Level Quantum Mechanics**