As the ongoing national indicator of what American students know and can do, the National Assessment of Educational Progress (NAEP) in Reading regularly collects achievement information on representative samples of students in grades 4, 8, and 12. Through The Nation's Report Card, the NAEP Reading Assessment reports how well students perform in reading various texts and responding to those texts by answering multiple-choice and instructed-response questions. The information NAEP provides about student achievement helps the public, educators, and policymakers understand strengths and weaknesses in student performance and make informed decisions about education. The 2013 NAEP Reading Assessment will measure national, regional, state, and sub-group achievement in reading but is not designed to report individual student or school performance. The assessment will measure students' reading comprehension and their ability to apply vocabulary knowledge to assist them in comprehending what they read. The reading assessment will use the same framework used in 2009. This document, the "Reading Framework for the 2013 National Assessment of Educational Progress," presents the conceptual base for, and discusses the content of, the assessment. It is intended for a broad audience. A more detailed technical document, the "Reading Assessment and Item Specifications for the National Assessment of Educational Progress," is available on the Web. The specifications will provide information to guide passage selection, item development, and other aspects of test development. The Governing Board, the policymaking body for NAEP, has stated that the NAEP Reading Assessment will measure reading comprehension by asking students to read passages written in English and to answer questions about what they have read. The NAEP Reading Framework results from the work of many individuals and organizations involved in reading and reading education, including researchers, policymakers, educators, and other members of the public. Their work was guided by scientifically based literacy research that conceptualizes reading as a dynamic cognitive process as reflected in the following definition of reading. Appended are: (1) Glossary of terms; (2) NAEP Reading Achievement Level Definitions; and (3) Special Studies: NAEP Reading Framework. A bibliography is included. (Contains 7 footnotes and 12 exhibits.)