The empirical relationships among about 90 reading objectives were examined. The objectives span late first-grade through the sixth-grade (nominally). The results of contingency analyses and correlational analyses are reported. The identification of learning hierachies is stressed. Such hierarchies are apparent in the early learning of reading skills, but reading tends to merge into a few major skills as proficiency is increased. The overall structure of the relationships among the 90 objectives is displayed and described. Implications are drawn for curriculum decisions, development of instructional materials, and test construction practices. (Author)