The study design and interim findings of the study conducted to determine the impact of bilingual education on students in the cognitive and affective domains in a nationally representative sample of Spanish/English bilingual projects are presented. The results summarized reflect the pre-post test period of data collection of the academic year 1975-76. Elementary students enrolled in bilingual projects were contrasted with students not enrolled in such projects. Standardized achievement tests were used to measure performance in language arts and mathematics computation in both languages. Information was collected on student and teacher characteristics and attitudes. Results from teacher questionnaires indicate that less than a third of all students in Title VII classrooms were there because of limited-English speaking ability. Title VII teachers and aides were more proficient in Spanish and English than non-Title VII staff. In terms of students of limited English-speaking ability achieving competency in English, projects which have been operating four to five years are said to not be generally effective. Encouraging results are said to be encountered in mathematics. It is claimed that no clear trend was found to indicate that participation in Title VII brought about an increase in positive attitude toward school. (CLK)