This report of the results of the 1974-75 Florida National Assessment Replication in reading and mathematics at the 9-, 13-, and 17-year-old age levels consists of several major parts: an overview of the assessment design and methodology, comparisons of performance levels for groups of Florida students within each age level, comparisons of performance levels for groups of Florida students across age levels, and comparisons of Florida performance levels with National Assessment performance levels. Chapter 2 describes the design and methodology of Florida's National Assessment Replication in reading and mathematics. Chapter 3 reports comparisons of reading and mathematics performance levels for groups of Florida 9-, 13-, and 17-year-olds classified by home, school, and student characteristics. The reporting variables are sex, race, size and type of community, parents' education, reading materials in the home, and Spanish as a native language. Chapter 4 compares reading and mathematics performance levels across ages on items administered at more than one age. Chapter 5 presents comparisons of reading and mathematics performance levels for Florida students and National Assessment groups at ages 9, 13, and 17. Comparisons are made between Florida and the Nation and between Florida and the Southeast. Comparisons are also made between groups of students from Florida and the Nation classified according to sex, race, size and type of community, and parents' education.(Author/MV) Aspect of National Assessment (NAEP) dealt with in this document: Procedures (Replication).