The adoption of Common Core State Standards in the USA by 46 states and the District of Columbia has provided several new foci for K-12 instruction, not the least of which is the reading and understanding of complex text, a higher order thinking process. Closely associated with this is the notion of rigor, the focus of the present study. As educators who work with administrators and teachers across the country, we have noticed that while there exists a general concern about rigor, there is not a coherent understanding of what it is. As such, there is a need to establish a common understanding of rigor that is useful for school-based personnel. Additionally, we propose that it's important for educators to regularly measure and track rigor as one part of a larger dashboard of quality indicators which can inform school leaders on the educational health of their school.