This document summarizes research related to improving student academic achievement. It identifies key variables that influence student achievement based on a review of over 800 meta-analyses. These variables are categorized into home context, school-level context, and classroom input variables. For each category, specific high-impact variables are identified based on an effect size threshold of 0.40 or greater. The document provides a framework for school improvement efforts to focus on the most important variables that research has shown can positively impact student achievement.