This study explored bilingual education in California, analyzing California law on instruction for English Learners before and after Proposition 227. Proposition 227 required that all English Learners (EL) participate in a sheltered English immersion program in which most instruction was in English with curriculum and presentation designed for children learning the language for a transition period not normally intended to exceed one year. This approach was designed to replace the existing system of bilingual education. The study also describes the process by which a child is designated limited English proficient or EL, the characteristics of these students, and trends in the number of students redesignated fluent-English-proficient. Also studied were bilingual education enrollment before and after Proposition 227 and the characteristics of students enrolled, testing rates for all EL students and EL students in bilingual education, and research findings on the effectiveness of bilingual education. Data came from the California State Department of Education database, classroom observations and interviews of teachers and principals, school documents, and findings from other research studies. Findings indicate that Proposition 227 may have a positive effect on the academic achievement of EL students, but it is not going to turn them into high scoring students. Bilingual education may not be an effective way of teaching EL students, but it was not the primary cause of their low achievement. In addition, redesignation standards are as problematic as ever, and may be more unrealistic than they were before Proposition 227. Some recommendations are made to amend Proposition 227. Ten appendices contain supplemental information about the study. (Contains 21 tables, 27 figures, and 70 references.) (SLD)