A review of research bearing on second language teaching methodology looks at what it tells about language processing and production, classroom interaction and second language learning, and learning strategy preferences. The perspective taken is that methodology consists of classroom tasks and activities. Implications of the research for the design of classroom tasks are then considered. Throughout, it is argued that language teaching methodology and materials should be based more firmly on empirical evidence about the nature of language, language learning, and language use. It is proposed that there exists much knowledge that can be exploited by materials designers and methodology experts to this end, and that there are areas into which research can be extended to broaden the knowledge base. In addition, a much closer relationship between research and teaching is recommended, implying both more interaction between teachers and researchers and greater teacher involvement in research. (MSE)