[3] The idea existed in the 1980s,[4][5] and has been reviewed and expanded upon by a number of other scholars but is usually credited to American psycholinguist Michael Long.
[7] In addition, it claims that the effectiveness of comprehensible input is greatly increased when learners have to negotiate for meaning.
[10] As a result, the interactional structure of a two-way conversation or task then elicits the most modifications since the dynamic aspect forces the participants to negotiate for meaning.
[12] A drawback is that in simplifying the input to make it comprehensible, modification takes away from the acquisition of complex structures.
[14] In a survey of the literature on the subject, Larsen-Freeman and Long say that interaction is not necessary for language acquisition; they do say, however, that it helps in certain circumstances.
Indirect evidence from past studies concerning L1 acquisition and sociolinguistic characteristics of non-native speakers are used to support the theory.
This idea that negotiating for meaning when there is a breakdown in communication is beneficial to language development is also tied to Merrill Swain's 1985 comprehensible output hypothesis which argues that the demands of negotiating ways to express output in a comprehensible manner for the interlocutor aids learners in their second language development.
[18] The revised version of the interaction hypothesis that is shown in Long's 1996 paper places more emphasis on noticing and corrective feedback.
[6] In her 1987 work in collaboration with Richard Young and Catherine Doughty titled "The Impact of Interaction on Comprehension"[19] Teresa Pica describes two kinds of linguistic environments in to which the interaction hypothesis applies: in which input is modified for the learner's comprehension, as found in instructional settings; and in which both conversation participants modify their own output so as to make themselves understood (i.e. when they both negotiate meaning) as found in naturalistic settings.
An example of this imbalance is students refraining from making clarification requests in effort to avoid their being perceived as challenging the teacher's knowledge.
Pica also explains that negotiations of meaning do not always elicit the modification result that is expected or intended from the learner.
Additionally, this revision would allow the theory to be tested empirically, since it more clearly defines the relationship between acquisition, comprehension, and input.
Ellis's later 2008 work titled The study of second language acquisition[21] relates the newer version of the interaction hypothesis to Focus-on-Form instruction which uses a communicative task with a focus on meaning to bring attention to form.
The learner may also focus too much on the meaning of the sentence that they have no leftover mental resources to pay attention to the linguistic features.