The Cooperative Language Development Project studied the efficacy of the Initial Teaching Alphabet (ITA) in teaching beginning reading and the efficacy of the Peabody Language Development Kits in stimulating verbal intelligence, creative thinking, school achievement, and language development. In this monograph, a post-test and follow-up evaluation are carried out after the fourth grade. Pupil progress was measured in various areas of standardized tests, such as the Stanford-Binet Intelligence Scale and the Torrance Tests of Creative Thinking. In general, the results are that some gains (in IQ, for example) from the original three-year program were not lost in the following year. In spite of some substantial and statistically significant decrements during the follow-up year, the results are considered to provide some optimism about the effectiveness of both experimental reading methods. However, until more sophisticated procedures and measures are available, it is not considered feasible to engage in additional teaching method studies. [For the interim report "after two years," see ED 017 415.] (Author/JW)