*65%*:**Student determination of differential area elements in upper-division physics***51%*:**Analytic framework for studentsâ€™ use of mathematics in upper-division physics***51%*:**Student responses to chain rule problems in thermodynamics***49%*:**Student Ideas around Vector Decomposition in the Upper Division***47%*:**Observations on student difficulties with mathematics in upper-division electricity and magnetism***47%*:**Students' understanding and application of the area under the curve concept in physics problems***45%*:**A Research-Based Approach to Assessing Student Learning Issues in Upper-Division Electricity & Magnetism***45%*:**Investigating student ownership of projects in an upper-division physics lab course***45%*:**Standing fast: Translation among durable representations using evanescent representations in upper-division problem solving***44%*:**Upper-division student understanding of Coulomb's law: Difficulties with continuous charge distributions***43%*:**Student expectations in a group learning activity on harmonic motion***42%*:**Upper-division students' difficulties with AmpĂ¨re's law***41%*:**Student Perspectives on Using Clickers in Upper-division Physics Courses***41%*:**Effects of Argumentation Scaffolds on Student Performance on Conceptual Physics Problems***41%*:**Student understanding of unit vectors and coordinate systems beyond cartesian coordinates in upper division physics courses***40%*:**Problem-based learning in upper division courses: Student successes, perceptions, and reactions***39%*:**Student understanding of basic probability concepts in an upper-division thermal physics course***39%*:**Towards an Understanding of How Students Use Representations In Physics Problem Solving***39%*:**Uptake of solution checks by undergraduate physics students**