The National Assessment of Educational Progress (NAEP) and its reports are a key measure in informing the nation on how well the goal of scientific literacy for all students is being met. The "Science Framework for the 2011 National Assessment of Educational Progress" sets forth the design of the NAEP Science Assessment. The 2011 NAEP Science Assessment will use the same framework used in 2009. The 2009 NAEP Science Assessment started a new NAEP science trend (i.e., measure of student progress in science), and the 2011 NAEP Science Report Card will include student performance trends from 2009 to 2011. Trends in student science achievement were reported from 1996 to 2005 as well. However, the trend from 1996 to 2005 was not continued due to major differences between the 2005 and 2009 frameworks. The new framework represents a unique opportunity to build on key developments in science standards, assessments, and research. This document is intended to inform the general public, educators, policymakers, and others about what students are expected to know and be able to do in science as part of The Nation's Report Card, a program of the U.S. Department of Education (ED) that reports on NAEP findings. This report contains the following chapters: (1) Overview; (2) Science Content; (3) Science Practices; and (4) Overview of the Assessment Design. Appendices include: (1) Steering Committee Guidelines; (2) NAEP Science Achievement Level Descriptions; (3) Sample Items and Scoring Guides; and (4) Group 2 Small-Scale Special Studies. A bibliography is included. (Contains 21 exhibits.)