1. Center for Research in Math and Science Education, San Diego State University, San Diego, California, United States
2. Department of Physics, California State University San Marcos, San Marcos, California, United States
3. Department of Physical Science, University of Central Missouri, Warrensburg, Missouri, United States
4. Department of Physics, University of Northern Iowa, Cedar Falls, Iowa, United States
5. Department of Physics, Northwestern Oklahoma State University, Alva, Oklahoma, United States
6. Department of Physics, University of Wisconsin - Whitewater, Whitewater, Wisconsin, United States
7. Department of Physics, University of Arkansas, Fayetteville, Arkansas, United States
8. Department of Physics and Astronomy, The University of Texas-Rio Grande Valley, Edinburg, Texas, United States