Second language research is important for teachers in bilingual programs because it investigates which solutions work best for which problems, in which situations, and with which learners. Research aids practitioners in more effective program planning, implementation, and evaluation. To compensate for the time lag in availability of materials, concerned teachers must keep up with current research, analyze its findings, and apply them to their teaching approaches and instructional materials. This paper presents: (1) an overview of major research areas in second language acquisition and refers to a sample of studies whose findings have clear implications for the classroom, (2) a second language learning model that incorporates many of the recent research findings into a taxonomic scheme, and (3) criteria and guidelines for applying second language acquisition research findings to the bilingual classroom. Four major areas of importance to the classroom teacher in current second language acquisition research are the comparison of first and second language acquisition; social, affective, and cognitive factors; second language input; and second language learning in school settings. (Author/JK)