The Discovery Research K-12 program (DRK-12) seeks to significantly enhance the learning and teaching of science, technology, engineering and mathematics (STEM) by preK-12 students and teachers, through research and development of innovative resources, models and tools (RMTs). Projects in the DRK-12 program build on fundamental research in STEM education and prior research and development efforts that provide theoretical and empirical justification for proposed projects.This project assesses the impact of scaling-up the teaching of physics and engineering to women students in grade levels 11 and 12, particularly in reference to retention. The problem of low participation of women in physics and engineering has been a topic of concern for decades. The persistent underrepresentation of women in physics and engineering is not just an equity issue but also reflects an unrealized talent pool that can help respond to current and future challenges faced by society. The aim is to mobilize high school physics teachers to "attract and recruit" female students into science (physics) and engineering careers. The fundamental issues that the project seeks is to affect increases in the number of females in physics and engineering careers using research-informed and field-tested classroom practices that improve female students' physics identity. The project will advance science (physics) identity research by testing research-based approaches/interventions with larger groups of teachers and connecting research to practice in ways that are both widely deployable and practical for teachers to implement. The project will also affect female participation in engineering since developing a physics identity is strongly related to choosing engineering. The core area teachers will be trained in addressing student identity as a physicist or engineer.In this project, two research universities (Florida International University, Texas A&M-Commerce) and the two largest national organizations in physics (American Physical Society and American Association of Physics Teachers) will work together using approaches/interventions drawn from prior research results that will be tested with teachers in three states (24 teachers, 8 in each state) using an experimental design with control and treatment groups. The project proposes three phases: 1. Refine already established interventions for improving female physics identity for use on a massive national level which will be assessed through previously validated and reliable surveys and sound research design; 2. Launch a massive national campaign involving workshops, training modules, and mass communication approaches to reach and attempt to mobilize 16,000 of the 27,000 physics teachers nationwide to attract and recruit at least one female student to physics using the intervention approaches refines in phase 1 and other classroom approaches shown to improve female physics identity; and 3. Evaluate of the success of the campaign through surveys of high school physics teachers (subjective data) and data from the Higher Education Research Institute to monitor female student increases in freshmen declaring a physics major during the years following the campaign (objective data). The interventions will focus on developing female students' physics identity, a construct which has been found to be strongly related to career choice and persistence in physics. The project has the potential to reduce or eliminate the gender gap in the field of physics. In addition, the increase in female physics identity is likely to also increase female representation in engineering majors. Therefore, the work will lay the groundwork for adapting similar methods for increasing under-representation of females in other disciplines. The societies involved (American Physical Society and American Association of Physics Teachers) are uniquely positioned within the discipline to ensure a successful campaign of information dissemination to physics teachers nationally and under-representation of females in other disciplines as well, engineering specifically.