The Significant Bilingual Instructional Features (SBIF) study identified, described, and verified features of bilingual instruction of a wide variety of limited English proficient students. It collected data on instructional organization, time allocation, classroom language use, active teaching behaviors, academic learning time, student participation styles, and classroom, school, and community context variables through a variety of quantitative and qualitative procedures. Part I involved the study of 58 classrooms and 232 students at six sites representing different ethnolinguistic (Mexican, Puerto Rican, Cuban, Cantonese, and Navajo) and multilinguistic groups. The classrooms were nominated for their success as settings for bilingual instruction. The instructional features identified as significant in this portion of the study include (1) congruence of instructional intent, (2) use of active teaching behaviors, (3) use of the students' native language and English for instruction, (4) integration of English language development with basic skills development, and (5) use of information from the students' home culture. Part II of the study verified the prevalence of those features in a second sample of 89 classrooms and 356 students at eight sites, including new sites representing Filipino, Vietnamese, and Hispanic ethnolinguistic groups. (MSE)