The fourth and final report on this study of the impact of bilingual education provides an overview of the design of the study and a summary of the findings, which were discussed in more detail in three previously released volumes. The goals of the study were to: (1) determine both the cognitive and the affective impact of bilingual education on students in Spanish/English bilingual education projects funded through ESEA Title VII, (2) describe the educational processes operating in these projects, (3) identify those educational practices which result in greater gains in student achievement, and (4) determine per-student costs associated with each project. Projects selected for the study were Title VII Spanish/English bilingual projects in either their fourth or fifth year of funding, as of fall 1975. The following topics are discussed: data collection strategy; data analysis strategy; types of students served by Title VII projects in the Study; educational goals; costs associated with Title VII Bilingual Project Schools and Non-Title VII Schools for 1975-76; characteristics of teachers and teacher aides, the impact of Title VII Programs on student achievement and attitudes; the relationship between gains in student achievement and attitudes and classroom procedures and environment and teaching staff characteristics. A list of the participating projects and school districts is included. (AMH)