*89%*:**Investigating student understanding of quantum physics: Spontaneous models of conductivity***53%*:**Investigating the Influence of Visualization on Student Understanding of Quantum Superposition***52%*:**Investigating student understanding of basic quantum mechanics in the context of time-dependent perturbation theory***50%*:**Investigating student understanding of quantum entanglement***49%*:**Addressing Student Models of Energy Loss in Quantum Tunneling***46%*:**The Influence of Student Understanding of Classical Physics When Learning Quantum Mechanics***44%*:**Student understanding of quantum mechanics***43%*:**Resources Students Use to Understand Quantum Mechanical Operators***43%*:**Improving students’ understanding of quantum measurement. I. Investigation of difficulties***43%*:**Improving students’ understanding of quantum measurement. II. Development of research-based learning tools***43%*:**Improving student understanding of addition of angular momentum in quantum mechanics***42%*:**A hierarchical model of the development of student understanding of momentum***42%*:**Testing the development of student conceptual and visualization understanding in quantum mechanics through the undergraduate career***42%*:**Surveying students' understanding of quantum mechanics in one spatial dimension***42%*:**Improving students' understanding of quantum mechanics via the Stern–Gerlach experiment***41%*:**Investigating student understanding in intermediate mechanics: Identifying the need for a tutorial approach to instruction***41%*:**Improving Students' Understanding of Quantum Mechanics***41%*:**Student Difficulties in Understanding Probability in Quantum Mechanics***41%*:**Assessing and improving student understanding of quantum mechanics**