Read the following statements about the Multidimensional Model:

I. – The focus is either on errors defined in terms of the mature second language (L2) system, or alternatively, on items held to be acquired when they are supplied 80 or 90 per cent accurately in obligatory contexts. Studying “acquisition”, in other words, mostly means assessing how far learners are from the finishing line or studying them as they cross it.

II. – The Model attempts to tie contextual factors to internal psycholinguistic processes. Thus, instead of the often rather vague claims in some theories for general effects of social and/or psychological factors on the Second Language Acquisition (SLA) product, typically defined by global proficiency test scores, the Multidimensional Model seeks to explain how such factors interact with cognitive mechanisms to produce precisely specified microlinguistic features.

III. – The Model predicts that the teachability of an item will always be constrained by its learnability. Once the underlying speech-processing prerequisites constitute an implicational hierarchy, the devices at one stage being part of what is required for operations at the next stage, none of the abstract stages of processing complexity can be bypassed. Items will only be successfully taught when learners are psycholinguistically “ready” to learn them.