*48%*:**Improving Student Understanding of Vector Fields in Junior-Level E&M***48%*:**Student understanding of unit vectors and coordinate systems beyond cartesian coordinates in upper division physics courses***42%*:**Writing Position Vectors in 3-d Space: A Student Difficulty With Spherical Unit Vectors in Intermediate E&M***37%*:**Tapping into Juniorsâ€™ Understanding of E&M: The Colorado Upper-Division Electrostatics (CUE) Diagnostic***35%*:**Longer term impacts of transformed courses on student conceptual understanding of E&M***33%*:**Students' difficulties with unit vectors and scalar multiplication of a vector***32%*:**Student Learning In Upper-Level Thermal Physics: Comparisons And Contrasts With Students In Introductory Courses***32%*:**Contrasts in Student Understanding of Simple E&M Questions in Two Countries***32%*:**Graphical representations of vector functions in upper-division E&M***32%*:**Upper-Level Physics Studentsâ€™ Conceptions Of Understanding***32%*:**Improving student understanding of Dirac notation by using analogical reasoning in the context of a three-dimensional vector space***30%*:**Testing Studentsâ€™ Understanding of Vector Concepts***30%*:**Test of understanding of vectors: A reliable multiple-choice vector concept test***29%*:**Student Ideas around Vector Decomposition in the Upper Division***28%*:**The Impact of the History of Physics on Student Attitude and Conceptual Understanding of Physics***27%*:**Research-Based Course Materials and Assessments for Upper-Division Electrodynamics (E&M II)***27%*:**Upper-division student understanding of Coulomb's law: Difficulties with continuous charge distributions***27%*:**Analysis of Student Understanding of Statics Principles***27%*:**Conceptual Understanding of Resistive Electric Circuits Among First-year Engineering Students**