Building the evaluation capacity of K-12 schools is clearly an important goal for the field of evaluation, especially in the current educational environment, which is dominated by issues of accountability and high-stakes testing. The focus on student achievement has forced schools to become more data-driven as they attempt to analyze test scores and make decisions about how students can improve scores the next year. To some extent, schools have become overwhelmed with data. State, district, and school- and classroom-level assessments have all led to more data than schools can reasonably manage. There is a need for schools to develop evaluation capacity to manage and use the multitude of data. As schools build evaluation infrastructure, administrators and teachers need support to develop evaluation knowledge and skills as well as increase their ability to conduct program evaluation. This article describes a new model of evaluation capacity building (ECB), one that advances notions of evaluation capacity building in STEM education and encourages new ways of thinking about ECB by linking concepts of organizational capacity building with the individual capacity building of K-8 teachers and graduate students. The project uses an immersion approach to develop the evaluation capacity of urban schools and of STEM graduate students. (Contains 2 figures.)