Results from the third national writing assessment of 17-year-old students conducted in 1979 by the National Assessment of Educational Progress (NAEP) are presented in this volume. Chapter one provides highlights of the results of the test assessment which indicate neither a major decline nor improvement in writing performance of 17-year-old students in general. Chapter two gives an overview of the NAEP assessments, a discussion of the populations assessed, a description of the written exercises, and descriptions of the methods of scoring: holistic, primary trait, analysis of rhetorical effectiveness, and analysis of syntax and mechanics. Chapter three provides an indepth discussion of the results, and chapter four gives an overview of the writing of 9-year-old, 13-year-old, and 17-year-old students. Chapter five offers some observations about writing in the United States and suggests implications of the results of the assessment for instruction. Appendixes include exercises, documentation, scoring guides, and sample papers; guidelines for syntax and mechanics analysis; group results and exercises evaluated for primary trait and cohesion; error frequencies for good and poor papers and selected groups; and the background questionnaire and group responses to background and attitude questions. (MKM) Primary type of information provided by report: Assessment Instrument (Released Exercises) (Scoring Guides); Results (Exercise Level).