Developed by Merrill Swain, the comprehensible output (CO) hypothesis states that learning takes place when encountering a gap in the linguistic knowledge of the L2. By noticing this gap the learner becomes aware of it and might be able to modify his output so that he learns something new about the language [1] Although Swain does not claim that comprehensible output is solely responsible for all or even most language acquisition, she does claim that under some conditions, CO facilitates second language learning in ways that differ from and enhance input due to the mental processes connected with the production of language.[2] This hypothesis is closely related to the Noticing hypothesis. Swain defines three functions of output: 1. Noticing function: Learners encounter gaps between what they want to say and what they are able to say and so they notice what they do not know or only know partially in this language. 2. Hypothesis-testing function: When learners say something there is always a hypothesis underlying e.g. about grammar. By uttering sth. the learners test this hypothesis and receive feedback from an interlocutor. This feedback enables them, if necessary, to reprocess their hypothesis. 3. Metalinguistic function: Learners reflect about the language they learn and hereby the output enables them to control and internalize linguistic knowledge.[3]
Swain的语言输出理论的英文版