This report supplies details of the design and data analysis of the 1986 National Assessment of Educational Progress (NAEP) to allow the reader to judge the utility of the design, data quality, reasonableness of assumptions, appropriateness of data analyses, and generalizability of inferences made from the data. After an introduction by A. E. Beaton, the following reports are included: (1) "Overview of Part I: The Design and Implementation of the 1986 NAEP" (A. E. Beaton); (2) "Developing the 1986 National Assessment Objectives, Items, and Background Questions" (I. V. S. Mullis, W. MacDonald, and N. A. Mead); (3) "Sample Design" (M. H. Hansen, K. Rust, and J. Burke); (4) "Instrument and Item Information" (J. R. Johnson); (5) "Field Administration" (N. Caldwell and R. Slobasky); (6) "Materials Processing and Database Creation" (J. L. Barone); (7) "Processing Assessment Materials" (A. M. Rogers and N. A. Norris); (8) "Professional Scoring" (A. Campbell); (9) "Data Transcription Systems" (A. M. Rogers); (10) "Editing Data" (A. M. Rogers); (11) "Quality Control of Data Entry" (J. J. Ferris); (12) "Database Creation" (A. M. Rogers); (13) "Public-Use Data Tape Construction" (A. M. Rogers); (14) "Overview of Part II: The Analysis of the 1986 NAEP" (A. E. Beaton); (15) "Scaling Procedures" (R. J. Mislevy); (16) "Reading Data Analysis" (R. Zwick); (17) "Mathematics Data Analysis" (E. G. Johnson); (18) "Science Data Analysis" (K. Yamamoto); (19) "Computer Competence Data Analysis" (N. A. Mead); (20) "History and Literature Data Analysis" (R. Zwick); (21) "Weighting Procedures and Variance Estimation" (E. G. Johnson, J. Burke, J. Braden, M. H. Hansen, J. A. Lago, and B. J. Tepping); and (22) "Statistical Summary of the 1986 NAEP Sample and Estimates of the Proficiencies of American Students" (A. E. Beaton, D. S. Freund, B. A. Kaplan, and M. A. Narcowich). A total of 169 tables and 8 figures illustrate the text. Six appendixes with 116 additional tables provide supplemental information about the research methodology. (Contains 60 references.) (SLD)