Second language curricula vary in their relative emphases on process and product and on the control exerted by the teacher and learner. Discourse analysis can be used to gain insight into classroom interaction. One model for this kind of analysis classifies utterances according to the structural predictions created by the preceding utterance, giving four minimal interaction units: initiation (I), response (R), response/initiation (R/I), and feedback (F). The typical classroom interaction takes the form I, R, F. Illocutionary acts (acts through which something is done when being uttered, e.g., "I promise") make up an illocutionary structure here as in other forms of discourse. Discourse may be seen as a goal or as a means in the classroom; the ideal is to achieve both functions. In product-based curricula, the teacher controls discourse, which is then necessarily limited. In process-based curricula, the responsibility of learning is given to the students, who have more illocutionary freedom and whose discourse better approaches the language outside the classroom. (MSE)