A study of the performance pattern of 1,000 elementary school children in Philadelphia was conducted to determine: (a) whether the inclusive Title I program was having a significant impact on reading achievement, and (b) whether the specific intervention models were producing significant changes in the performance rates of their respective groups. Through the use of a component impact analysis procedure, it has been found that Title I elementary schools in Philadelphia were receiving four intervention models: Educational and Cultural Enrichment, General Instructional and Supportive Support, Intensive Instructional and Supportive Support, and Remediation Programs. The evaluation of the scores of 1,000 pupils from the target population revealed that the four intervention models were producing positive differential gains in reading achievement. When compared with their initial rates of progress, the average pupil increased his rate of progress in reading achievement by 100 percent. In Models 2, 3, and 4, the average pupil improved his rate of progress in reading by more than 100 percent. These results showed that the additive effects of the project input service configurations within the intervention models caused the development of skills/strategies which facilitate improved learning. (Author/JM)