This discussion of the development of oral proficiency in a second language first examines relevant research and then suggests guidelines for designing classroom techniques for teaching oral proficiency. Research in cognitive psychology is reviewed, focusing on information processing theory and forgetting theory. Research discussed in the area of second language acquisition includes optimal input, repeated practice, and positive affect. Four principles for oral proficiency development drawn from the research are: (1) repeated practice is necessary for fluency; (2) increased practice creates conditions for restructuring; (3) optimal practice activities should be comprehensible, interesting, relevant, challenging, and in sufficient quantity; and (4) optimal practice activities should be meaning-focused and communicative in nature. Eight characteristics of effective instruction based on these principles are outlined, and ways in which they can be incorporated into instruction for developing oral proficiency are suggested. The eight characteristics include the following: attainable and challenging objectives; learner understanding of content; varied context for linguistic patterns to be learned; spiraled sequencing; minimal correction; use of motivating games; combination of formal and informal settings for instruction; and periodic testing. A 23-item bibliography and instructional examples are appended. (MSE)