The PISA 2006 definition of scientific literacy had its origin in the consideration of what 15-year old students should know, value, and be able to do as a preparedness for life in modern society. The results of PISA Science 2006 provide important insights into scientific literacy. Although developed specifically for the assessment, the framework described in this chapter should help science teachers align their curricula, instruction, and classroom assessments with the goal of attaining higher levels of scientific literacy for all students.