2012 National Survey of Science and Mathematics Education: Science Teacher Questionnaire solicits information regarding K-12 science teachers' opinions, their preparation, and their teacher practice. The questionnaire was developed and administered to a nationally representative sample of science teachers as part of the 2012 National Survey of Science and Mathematics Education. All of the participating teachers answered a core set of items (about 25-30 minutes of survey time). In addition, teachers were randomly assigned to one of two sets of additional items, Matrix A or Matrix B (about 10-15