This Policy Brief describes an analysis conducted with a sample of 5,000 elementary students in 123 K-6 elementary schools in Hawai'i to describe students' proficiency levels and individual growth patterns over time and, based on this information, to make judgments about school effectiveness in meeting performance standards. The goal was to illustrate how growth modeling can be used to monitor levels of proficiency, while also adding another, more equitable, way of looking at school progress--one that is more directly related to what schools do in educating students, as opposed to what critics suggest currently merely reflects the demographic characteristics of school communities. The second part of the study focused on what school-related variables best explain the classification of schools into their proficiency-growth groups. Further analyses revealed two sets of possible explanatory variables: a "school contextual dimension" and a "school process dimension." Policy recommendations are provided from the study.