In response to concern about the effectiveness of programs for English-as-a-Second-Language students in California's schools, the Santa Ana Unified School District, in which over 80 percent of students are limited-English-proficient (LEP) conducted a study of both the operations and effectiveness of the district's language development program, using data accumulated over several years. The findings, documented in this report, cover five broad areas: information system reliability; language development services for LEP students; development of English fluency; impacts on reading and mathematics achievement; and an analysis of school attendance data. The report concludes with 14 recommendations for action in three areas: improving language development program effectiveness; improving data systems operations; and further study. Appended materials detail the technical aspects of the study. Contains 35 references. (MSE)