Caveat: Being an adaptation of a section of a chapter in my Doctoral thesis, this is a fairly challenging article which may require solid grounding in Applied Linguistics and Cognitive Theories of Skill Acquisition.
1. L2-Acquisition as skill acquisition: the Anderson Model
Although ACT* constitutes my espoused theory of L2 acquisition, I do not endorse Anderson’s claim that his model alone can give a completely satisfactory account of L2-acquisition. I do believe, however, that it can be used effectively to conceptualise at least three important dimensions of L2-acquisition which are relevant to type of Explicit MFL instructional approaches implemented in many British schools: (1) the acquisition of grammatical rules in explicit L2-instruction, (2) the developmental mechanisms of language processing and (3) the acquisition of Learning Strategies.
Figure 1: The Anderson Model (adapted from Anderson, 1983)
The basic structure of the model is illustrated in Figure 1, above. Anderson posits three kinds of memory, Working Short-Term Memory (WSTM), Declarative Memory and Production (or Procedural) Memory. Working Memory shares the same features discussed in previous blogs (see ‘Eight important facts about Working Memory’) while Declarative and Production Memory may be seen as two subcomponents of Long-Term Memory (LTM). The model is based on the assumption that human cognition is regulated by cognitive structures (Productions) made up of ‘IF’ and ’THEN’ conditions. These are activated every single time the brain is processing information; whenever a learner is confronted with a problem the brain searches for a Production that matches the data pattern associated with it. For example:
IF the goal is to form the present perfect of a verb and the person is 3rd singular/
THEN form the 3rd singular of ‘have’
IF the goal is to form the present perfect of a verb and the appropriate form of ‘have’ has just been formed /
THEN form the past participle of the verb
The creation of a Production is a long and careful process since Procedural Knowledge, once created, is difficult to alter. Furthermore, unlike declarative units, Productions control behaviour, thus the system must be circumspect in creating them. Once a Production has been created and proved to be successful, it has to be automatised in order for the behaviour that it controls to happen at naturalistic rates. According to Anderson (1985), this process goes through three stages: (1) a Cognitive Stage, in which the brain learns a description of a skill; (2) an Associative Stage, in which it works out a method for executing the skill; (3) an Autonomous Stage, in which the execution of the skill becomes more and more rapid and automatic.
In the Cognitive Stage, confronted with a new task requiring a skill that has not yet been proceduralised, the brain retrieves from LTM all the declarative representations associated with that skill, using the interpretive strategies of Problem-solving and Analogy to guide behaviour. This procedure is very time-consuming, as all the stages of a process have to be specified in great detail and in serial order in WSTM. Although each stage is a Production, the operation of Productions in interpretation is very slow and burdensome as it is under conscious control and involves retrieving declarative knowledge from LTM. Furthermore, since this declarative knowledge has to be kept in WSTM, the risk of cognitive overload leading to error may arise.
Thus, for instance, in translating a sentence from the L1 into the L2, the brain will have to consciously retrieve the rules governing the use of every single L1-item, applying them one by one. In the case of complex rules whose application requires performing several operations, every single operation will have to be performed in serial order under conscious attentional control. For example, in forming the third person of the Present perfect of ‘go’, the brain may have to: (1) retrieve and apply the general rule of the present perfect (have + past participle); (2) perform the appropriate conjugation of ‘have’ by retrieving and applying the rule that the third person of ‘have’ is ‘has’; (3) recall that the past participle of ‘go’ is irregular; (4) retrieve the form ‘gone’.
Producing language by these means is extremely inefficient. Thus, the brain tries to sort out the information into more efficient Productions. This is achieved by Compiling (‘running together’) the productions that have already been created so that larger groups of productions can be used as one unit. The Compilation process consists of two sub-processes: Composition and Proceduralisation. Composition takes a sequence of Productions that follow each other in solving a particular problem and collapses them into a single Production that has the effect of the sequence. This process lessens the number of steps referred to above and has the effect of speeding up the process. Thus, the Productions
P1 IF the goal is to form the present perfect of a verb / THEN form the simple present of have
P2 IF the goal is to form the present perfect of a verb and the appropriate form of ‘have’ has just been formed / THEN form the past participle of the verb would be composed as follows:
P3 IF the goal is to form the present perfect of a verb / THEN form the present simple of have and THEN the past participle of the verb
An important point made by Anderson is that newly composed Productions are weak and may require multiple creations before they gain enough strength to compete successfully with the Productions from which they are created. Composition does not replace Productions; rather, it supplements the Production set. Thus, a composition may be created on the first opportunity but may be ‘masked’ by stronger Productions for a number of subsequent opportunities until it has built up sufficient strength (Anderson, 2000). This means that even if the new Production is more effective and efficient than the stronger Production, the latter will be retrieved more quickly because its memory trace is stronger.
The process of Proceduralisation eliminates clauses in the condition of a Production that require information to be retrieved from LTM memory and held in WSTM. As a result, proceduralised knowledge becomes available much more quickly than non-proceduralised knowledge. For example, the Production P2 above would become
IF the goal is to form the present perfect of a verb
THEN form ‘had’ and then form the past participle of the verb
The process of Composition and Proceduralisation will eventually produce after repeated performance:
IF the goal is to form the present perfect of ‘play’/ THEN form ‘ has played’
For Anderson it seems reasonable to suggest that Proceduralisation only occurs when LTM knowledge has achieved some threshold of strength and has been used some criterion number of times. The mechanism through which the brain decides which Productions should be applied in a given context is called by Anderson Matching. When the brain is confronted with a problem, activation spreads from WSTM to Procedural Memory in search for a solution – i.e. a Production that matches the pattern of information in WSTM. If such matching is possible, then a Production will be retrieved. If the pattern to be matched in WSTM corresponds to the ‘condition side’ (the ‘if’) of a proceduralised Production, the matching will be quicker with the ‘action side’ (the ‘then’) of the Production being deposited in WSTM and make it immediately available for performance (execution). It is at this intermediate stage of development that most serious errors in acquiring a skill occur: during the conversion from Declarative to Procedural knowledge, unmonitored mistakes may slip into performance.
The final stage consists of the process of Tuning, made up of the three sub-processes of Generalisation, Discrimination and Strengthening. Generalisation is the process by which Production rules become broader in their range of applicability thereby allowing the speaker to generate and comprehend utterances never before encountered. Where two existing Productions partially overlap, it may be possible to combine them to create a greater level of generality by deleting a condition that was different in the two original Productions. Anderson (1982) produces the following example of generalization from language acquisition, in which P6 and P7 become P8
P6 IF the goal is to indicate that a coat belongs to me THEN say ‘My coat’
P7 IF the goal is to indicate that a ball belongs to me THEN say ‘My ball’
P8 IF the goal is to indicate that object X belongs to me THEN say ‘My X’
Discrimination is the process by which the range of application of a Production is restricted to the appropriate circumstances (Anderson, 1983). These processes would account for the way language learners over-generalise rules but then learn over time to discriminate between, for example, regular and irregular verbs. This process would require that we have examples of both correct and incorrect applications of the Production in our LTM.
Both processes are inductive in that they try to identify from examples of success and failure the features that characterize when a particular Production rule is applicable. These two processes produce multiple variants on the conditions (the ‘IF’ clause(s) of a Production) controlling the same action. Thus, at any point in time the system is entertaining as its hypothesis not just a single Production but a set of Productions with different conditions to control the action.