Despite our best and most sincere efforts, there is an alarming disconnect between what we teach and what students learn and understand. The goal of physics education research is to help close this gap. I will discuss, using my own research and activities as examples, the three major components of physics education research: (1) Identification of student difficulties, (2) curriculum/pedagogy development to minimize the sources of these difficulties, and (3) implementation/evaluation of new pedagogy and teaching methods. My own research has emphasized student understanding of basic (energy/momentum) and advanced (quantum mechanics) concepts, and has strived to find common origins for the ways in which misconceptions arise. I am working on developing teaching strategies that actively involve students in the learning process. Some instructional strategies involve little or no extra effort on the part of the instructor. At the University of Pittsburgh, I have created (with NSF and University support) a Physics Exploration Center (PEC) that allows students to become more familiar with the phenomena that are explained by physics. I am also developing a set of problem-solving videos to help students work “offline” on their analytical skills. I will discuss how I use and refine these teaching methods, and evaluate their effectiveness using a variety of methodologies.