The NGSS Evidence Statements for high school are now available. These statements were developed by educators and scientists, including many members of the NGSS writing team. The evidence statements provide additional detail on what students should know and be able to do in order to satisfy each performance expectation (PE) at the end of instruction. Given that each PE is three-dimensional, the statements describe how students will use the practices, crosscutting concepts, and disciplinary core ideas together to demonstrate proficiency on the PEs by the end of instruction. The evidence statements are intended to identify clear, measurable components that, if met, fully satisfy each PE described within the NGSS. They are not meant to limit or dictate instruction and were written to allow for multiple methods and contexts of assessment, including assessing multiple related PEs together at the same time. For more information, see the Front Matter.