*54%*:**Investigating Student Difficulties with Time dependence of Expectation Values in Quantum Mechanics***52%*:**Investigating Student Understanding of Perturbation Theory and the Inner Products of Functions***46%*:**Improving Students' Understanding of Quantum Mechanics***40%*:**Surveying students' understanding of quantum mechanics in one spatial dimension***39%*:**Improving students’ understanding of quantum measurement. II. Development of research-based learning tools***38%*:**Improving student understanding of addition of angular momentum in quantum mechanics***37%*:**Exploring Student Understanding of Energy through the Quantum Mechanics Conceptual Survey***37%*:**Student understanding of potential, wavefunctions and the Jacobian in hydrogen in graduate-level quantum mechanics***36%*:**Student difficulties with determining expectation values in quantum mechanics***36%*:**Student Understanding of Period in Introductory and Quantum Physics Courses***35%*:**Using student-generated content to engage students in upper-division quantum mechanics***34%*:**Conceptual Understanding of Quantum Mechanics: An Investigation into Physics Students’ Depictions of the Basic Concepts of Quantum Mechanics***34%*:**Developing and evaluating an interactive tutorial on degenerate perturbation theory***34%*:**The Influence of Student Understanding of Classical Physics When Learning Quantum Mechanics***34%*:**Surveying Students’ Understanding of Quantum Mechanics***34%*:**Improving Students’ Understanding of Quantum Measurement***33%*:**Testing the development of student conceptual and visualization understanding in quantum mechanics through the undergraduate career***33%*:**Student Difficulties in Understanding Probability in Quantum Mechanics***33%*:**Assessing and improving student understanding of quantum mechanics**