The Significant Bilingual Instructional Features (SBIF) descriptive study, completed in 1983, sought to identify, describe, and verify instructional features that appear to be successful in producing positive classroom experiences and learning outcomes for limited English proficient (LEP) students. SBIF findings are integrated in this report with other research to describe successful instruction for LEP students. The report's five chapters concern: (1) five significant bilingual instructional features (active learning behavior, use of both native language and second language in instruction, integration of English language development with academic skills development, response to and use of information from LEP students' home culture, and effective organizational and delivery of instruction); (2) the demands of instruction for LEP students; (3) developing student functional proficiency; (4) mediation of effective bilingual instruction; and (5) the SBIF study in perspective: implications and issues. Appended is an overview of the SBIF study. Contains 49 references. (LB)