This update summarizes the first 2 years of a 5-year evaluation of the implementation of California's Proposition 227 (which replaces the state's bilingual education programs with 1-year English immersion programs) and its effects on the education of English language learners (ELLs). Researchers used the percentage of ELLs receiving primary language instruction at a school in 1997-1998, before Proposition 227, and 3 years later to classify three types of schools: continuing bilingual, never bilingual, and transitioning from bilingual. Results suggest that only 15 percent of California schools were substantially impacted by Proposition 227. However, the Proposition did affect a substantial portion of the state's ELLs enrolled in bilingual programs. Prior to Proposition 227, 29 percent of ELLs were receiving bilingual education. In 2002, that figure dropped to 11 percent. While ELLs scored significantly lower on standardized tests than their native English speaking peers, the performance gap was closing slightly. All three types of schools were equally effective in raising ELLs' achievement. Interviews with key stakeholders reported mixed or neutral effects of Proposition 227 on educational quality for ELLs. However other findings suggest that curriculum for ELLs may be watered down. Fifteen recommendations for education leaders and policymakers are included. (SM)