ABSTRACT
As VanPatten and Williams note in Chapter 1 , a distinction needs to be made between models and theories. Notably, they distinguish between the how and the why . They also describe hypotheses, which differ from theories in that a hypothesis “does not unify various phenomena; it is usually an idea about a single phenomenon.” This chapter deals with input, interaction, feedback, and output in second language acquisition. These constructs have been integrated and were originally referred to as the Interaction Hypothesis. However, following a significant amount of empirical work leading to greater specificity and theoretical advancement, it is now generally referred to in the literature as the interaction approach .
