This document describes the features of a statewide summative science assessment that has been designed to embody standards based on the "Framework for K-12 Science Education," such as the Next Generation Science Standards (NGSS)--to reflect its intent, grounded in the specific expectations of three-dimensional standards. Importantly, this document outlines the expectations for high-quality statewide summative science assessments that are designed and administered, in part, to meet federal requirements for science testing under Title I Part A of the Every Student Succeeds Act. As such, the criteria and evidence described here are grounded in the expectations outlined in the "Framework" and the NGSS as well as those described by federal peer review guidelines. In other words, while the priority for these criteria is to embody the intent of the NGSS and "Framework," they are intentionally bounded by what would be needed and feasible to meet federal expectations for statewide summative assessments. This document is intended to support state assessment directors, science supervisors, science assessment leads, test developers, and organizations that conduct independent evaluations of alignment of statewide summative assessments to state standards.