Information Processing Model

The Information Processing Model of SLA, articulated by Barry McLaughlin (1983, 1987), frames second language learning as the acquisition of a complex cognitive skill. The central mechanism is the shift from controlled processing (slow, attention-demanding, capacity-limited) to automatic processing (fast, effortless, capacity-free) through practice. This is the same mechanism that governs the acquisition of any complex skill, from driving a car to playing chess.

Controlled vs. Automatic Processing

McLaughlin drew on Shiffrin and Schneider's (1977) distinction between two modes of information processing:

Feature	Controlled processing	Automatic processing
Attention	Requires focal attention	Does not require attention
Capacity	Limited by short-term memory	Uses little or no processing capacity
Speed	Slow	Fast
Flexibility	Can be applied to new situations	Difficult to modify once established
Awareness	Typically conscious	Typically below awareness
Development	Present from the start of learning	Develops through extensive practice

In early L2 learning, virtually all processing is controlled. A beginning learner constructing a sentence must consciously attend to word choice, morphology, word order, and pronunciation simultaneously — quickly exceeding attentional capacity. This is why beginners speak slowly, make errors under time pressure, and cannot attend to meaning and form at the same time.

Restructuring

McLaughlin (1990) emphasised that automatisation is not the only developmental mechanism. Restructuring also occurs: as learners gain proficiency, they do not simply speed up existing representations — they reorganise their internal representations of the L2. This can produce temporary decreases in performance (U-shaped development) as old representations are dismantled and new, more efficient ones are constructed.

The interaction of automatisation and restructuring explains a common observation: learners sometimes appear to regress (e.g., producing errors on forms they previously used correctly) precisely when they are making progress — the system is reorganising.

Relationship to Other Frameworks

The Information Processing Model is the direct precursor to Skill Acquisition Theory (Anderson, 1983; DeKeyser, 1998), which formalises the transition from declarative to procedural knowledge through three stages (cognitive → associative → autonomous). McLaughlin's model is broader but less specific — it does not commit to the ACT-R architecture that Skill Acquisition Theory adopts.

The model also connects to Attention in SLA and the Noticing Hypothesis (Schmidt, 1990). If controlled processing requires attention, then the features of the L2 that learners attend to are the ones most likely to enter the system. Schmidt's claim that Noticing is necessary for acquisition can be seen as a refinement of McLaughlin's attention-based framework.

Criticisms

• Vagueness — the model describes a general mechanism (controlled → automatic) but does not specify what is being automatised or how restructuring occurs at the linguistic level
• Underspecification of the role of meaning — the model treats L2 learning as skill acquisition but says relatively little about the role of communicative meaning, social interaction, or the content of input
• Difficulty distinguishing from Skill Acquisition Theory — the two frameworks overlap substantially, and Skill Acquisition Theory has largely superseded McLaughlin's model by providing a more detailed cognitive architecture

Teaching Implications

• Practice is essential — the shift from controlled to automatic processing requires extensive, sustained practice with L2 forms in meaningful contexts
• Reducing cognitive load — tasks should be designed to avoid overwhelming learners' limited processing capacity, particularly in early stages
• Accuracy under time pressure is a good diagnostic — if learners can produce correct forms only when they have unlimited time, the forms are still under controlled processing
• Automaticity in one area frees up attentional resources for others — automatising basic vocabulary and high-frequency structures allows learners to attend to more complex aspects of the L2