At Marylin Avenue School in Livermore, California, student achievement more than doubled from 2006 to 2013, even as the number of socioeconomically disadvantaged students increased from 66% to 88% and English language learner populations from 57% to 64%. Key to this continued growth in student achievement was the evolution of strategies that allowed teachers to continuously learn together and from each other to improve their practice. These strategies include the data team process, lesson study, peer observations, and lab lessons. Using these practices together, teachers identified needs, set goals, and planned professional learning that was job-embedded, ongoing, and focused on the curriculum being taught (Odden, 2009). Marylin’s learning system allowed teachers to take risks and innovate and encouraged everyone to measure for effectiveness. Any school