This document discusses the importance of using assessment data to improve teaching and learning. It advocates being "knowledge-driven" rather than just "data-driven" and using data to identify what students know and don't know in order to adjust instruction. The document outlines an approach involving multiple measures, school-wide goals, and regular data analysis within professional learning communities. The goals are to support student growth, engage students through differentiated instruction, and use formative and summative assessments in an ongoing cycle of reflection, planning, assessment, and action.