Understanding Second Language Acquisition (2nd ed)

by Rod Ellis

  11

  The role of implicit instruction

  Introduction

  In the last chapter, we examined the research that has investigated the role of explicit instruction, defined as instruction that invites intentional learning of specific features of the second language (L2) and typically includes explicit information about the target feature. In this chapter, we will consider research that has investigated the role of implicit instruction, which I have defined as instruction that caters to incidental acquisition and aims to attract rather than direct attention to form. See Table 10.1 for a more detailed specification of the differences between these two types of instruction.

  Implicit instruction needs to be distinguished from implicit learning. In Chapter 8, I defined implicit learning as learning that takes place without any awareness. I also noted that there is disagreement as to whether in fact any learning can occur without some level of awareness—for example, awareness at the level of ‘noticing’. Implicit instruction does not assume that the learning that results is necessarily of the implicit kind. Indeed, a major feature of most types of implicit instruction is that learners attend, albeit unobtrusively, to linguistic form and that this is necessary for acquisition to occur. It is for this reason that I have defined implicit instruction as instruction aimed at facilitating incidental acquisition—i.e. the picking-up of linguistic features when learners are not making deliberate efforts to learn them. However, when learners learn incidentally, they may well pay conscious attention to specific target features and this noticing may be needed for learning to take place. Implicit instruction, however, does not aim at inducing metalinguistic understanding of target features and it is in this respect that it differs most clearly from explicit instruction.

  Theoretical issues in implicit instruction

  The rationale for implicit instruction draws on a number of theoretical constructs that we have considered in previous chapters. First, it assumes that incidental acquisition is possible—even by adults: learners do not have to be told what it is they are supposed to learn. Indeed, in implicit instruction, learners are not told what the target of the instruction is. Rather—as Housen and Pierrard (2006) put it—the instruction is designed so as to ‘attract attention to the target form’. Second, it can be argued that incidental acquisition is the main way in which learners develop high levels of proficiency in an L2. Krashen (1982) pointed out that there are limits to how much learners can deliberatively ‘learn’—i.e. as explicit knowledge—and that they need opportunities to ‘acquire’ implicit knowledge. It is difficult to see how the kind of elaborate connectionist network that comprises implicit knowledge—see Chapter 8—can be constructed other than through incidental acquisition. In other words, implicit instruction can help learners to acquire the kind of capacity needed to engage in communication. Of course, this is not to deny a role for explicit instruction, but rather to point out that it is not sufficient.

  Focus-on-form

  Arguably, the key theoretical construct that informs implicit instruction is focus-on-form (Long 1991). In Chapter 7, I introduced this construct to explain how input and interaction provide opportunities for learners to attend to linguistic form while they are primarily focused on meaning. Implicit instruction aims not just to expose learners to the target language, but to do so in ways that will induce incidental attention to linguistic forms. In Chapter 7, I examined various ways in which this can take place, for example by pre-modifying the input that learners are required to comprehend and through the interactionally modified input, corrective feedback, and pushed output, which can arise when negotiating a communication or linguistic problem. Activities that give rise to focus-on-form, then, have a central role in implicit instruction. They provide the means for ensuring that noticing and pushed output take place. In Chapter 10, we noted that focus-on-form activities also play a part in explicit instruction; in particular in the free production stage of a lesson. In implicit instruction, however, such activities comprise the totality of the instruction; that is, there is no explicit presentation of the instructional targets. Attention to form only occurs while learners are experiencing use of the L2.

  Limited resources model

  However, not all implicit instruction has been based on focus-on-form – or, at least, not as defined by Long. Skehan (1998) draws on his Dual-Mode Model (see Chapter 8) as a basis for his own proposals for implicit instruction. This model is premised on the assumption that learners have limited processing capacity and thus will experience difficulty in focusing on form and meaning at the same time and, thus, will need to prioritize one or the other at different times by accessing either their rule-based system (when concerned primarily with form) or their exemplar-based system (when concerned primarily with meaning). Skehan distinguishes three aspects language production: complexity, accuracy, and fluency (CAF) (see Table 11.1)NOTE 1.

  Aspects of language production Description

  Complexity The extent to which the learner produces more complex constructions using the rule-based system. It is distinguished from ‘accuracy’ in that it demonstrates that the learner is taking the risks that will lead to ‘restructuring’ of the L2 system.

  Accuracy The extent to which the learner conforms to target language norms. Accuracy is achieved by the learner drawing on the rule-based system and engaging in syntactic processing in order to avoid making errors.

  Fluency The extent to which the learner can speak rapidly without undue pausing, repetition, or reformulation. Fluency is achieved by drawing on ready-made chunks of language and by using communication strategies to address any problems that arise.

  Table 11.1 Three aspects of language production as described by Skehan (1998)

  Skehan’s principal argument is that instruction needs to create the cognitive conditions that will cause learners to prioritize one aspect of production over another. His Trade-off Hypothesis proposes that learners will prioritize one aspect of production over the others. Implicit instruction for Skehan, then, is not a means for attracting learner’s attention to specific linguistic forms (as in focus-on-form) but rather as a means for orienting learners generally to either meaning or form and—in the case of the latter—to either accuracy or complexity.

  To explain how this takes place Skehan (2009) drew on Levelt’s (1989) Model of Speech Production. This distinguishes three basic processes: ‘conceptualization’, ‘formulation’, and ‘articulation’. Conceptualization concerns the propositional content of the message that a speaker wishes to convey and its communicative intent. Formulation involves developing a linguistic plan for encoding the propositional content by accessing lexis and grammar from long-term memory. Articulation occurs when the plan is performed. In native speakers, these phases occur in parallel. However, L2 learners, especially those with limited proficiency, have difficulty in executing the three phases simultaneously, and thus engage in more linear processing. Thus, if they first conceptualize what they want to say before having to speak, they will then be able to allocate greater attention to formulation and articulation. This—Skehan suggested—results in language that is both more fluent and more complex, but not necessarily more accurate. If they are pressured to conceptualize, formulate, and perform messages in parallel, L2 learners’ speech becomes less fluent and less complex. When they talk about a very familiar topic there is less need to conceptualize, allowing more time for formulation. In this case—because the message-content is ready-made and they do not need to express complex ideas—they can concentrate on accuracy. Skehan also pointed out that when learners have difficulty in formulating a message—in particular because of limitations in their mental lexicon—they are likely to resort to communication strategies, such as avoidance, circumlocution, and paraphrase: for example, if they do not know or cannot access the lexical item ‘gallery’ they might paraphrase its meaning by saying ‘place with pictures on the walls’.

  In effect, Skehan envisages a tension between performance and acquisitio
n. In performance, learners need to prioritize meaning when they are communicating; however, acquisition requires that they also attend to form so that new linguistic material can be transferred from working memory to long-term memory. Thus, the role of implicit instruction is to balance the demands of performance with the requirements of acquisition. Skehan argued that asking learners to perform communicative tasks that pose varying processing demands on them can guide learners to focus their attention on specific aspects of language and thus help to ensure balanced language development.

  The Cognition Hypothesis

  As we will see later, Skehan’s research has focused on identifying the design features of tasks and the different ways of implementing them that predispose learners to attend to a specific aspect of production. Robinson’s (2007) Cognition Hypothesis has a similar goal. It constitutes a framework for classifying the relevant design and implementation variables that influence complexity, accuracy, and fluency. Robinson (2001) distinguished ‘resource-directing’ variables and ‘resourced-dispersing’ variables of a task. The former affect the demands the task can make on the learner’s attention and—in so doing—cause the learner to focus on specific linguistic forms (i.e. accuracy and complexity) and thus potentially promote interlanguage development. Task variables that are resource-directing include whether the task requires: (1) reference to events happening in the ‘here-and-now’ or to events that took place in the past elsewhere (in the ‘there-and-then); and (2) transmission of simple information or provision of reasons for intentions, beliefs, or relations. Resource-dispersing variables affect the procedural demands on the learners’ attentional and memory resources, but do not affect the extent to which they draw attention to specific linguistic forms. They do not promote the acquisition of new L2 forms, but do enhance automaticity (i.e. fluency). Examples are (1) providing pre-task planning time, and (2) whether or not a task has a clear structure.

  There is also a third set of variables in Robinson’s model which influence how learners respond to implicit instruction: ‘task difficulty’. These involve factors relating to the learner rather than the complexity of the task itself. Robinson identifies two sets of learner factors that influence how learners respond to an activity: cognitive factors—i.e. working memory and reasoning skills—and affective factors—motivation and language anxiety.

  Based on the Cognition Hypothesis, Robinson makes somewhat different predictions from those of Skehan. Skehan argues that the nature of the task will not just predispose learners to attend to fluency or form, but that it will also lead them to focus on a specific aspect of form—i.e. either accuracy or complexity. Robinson, however, sees the essential trade-off as being between fluency and form: a task which is complex in terms of resource-directing variables will cause learners to make greater effort to control and monitor their production, thus affecting both accuracy and complexity. He argued that ‘pedagogic tasks should be sequenced solely on the basis of increases in their cognitive complexity’ (Robinson 2011: 14).

  Robinson (2007) further developed his model into what he called ‘The Triadic Framework for Task Classification’. The three parts of the model are: (1) ‘task complexity’—which included the resource-directing and resource-dispersing variables; (2) ‘task condition’—which covered participation and participant variables (for example, whether the task required one-way or two-way interaction and whether the task participants were familiar with each other); and (3) ‘task difficulty’. The main addition in this later framework, then, was a list of variables relating to ‘task condition’. These were hypothesized to affect the quantity and quality of the interactions that occur when a task is performed—for example, negotiation of meaning. These variables, however, are only relevant to tasks that require learners to interact (i.e. dialogic tasks).

  Types of implicit instruction

  The various types of implicit instruction are shown schematically in Figure 11.1 and described below. In Chapter 8, I considered how implicit learning is investigated in cognitive psychology. Typically, this involves asking participants to memorize a set of sentences which provide exemplars of particular syntactic structures and then assessing whether the participants can distinguish whether new sentences containing the same structures are grammatical or ungrammatical. Implicit learning is said to have taken place if the participants are able to judge the grammaticality of the new sentences correctly, but are unable to report how they made their judgements. This approach has also been used in some SLA studies—for example N. Ellis (1993) and Robinson (1996). Asking learners to memorize sentences can be considered a type of implicit instruction. However, it is not a type that figures in language pedagogy.

  Figure 11.1 Types of implicit instruction

  Implicit instruction in language pedagogy is meaning centred: it involves engaging learners in the comprehension and production of the L2 for a communicative purpose. Two broad types of such instruction can be distinguished, the first of which is entirely meaning focused; that is to say, there is no attempt to attract the learners’ attention to form. Examples of this type are extensive reading and Krashen and Terrell’s (1983) Natural Approach. In both ‘acquisition’ (as defined by Krashen 1981) is claimed to occur automatically, as in L1 acquisition when learners comprehend inputNOTE 2.

  The second type is also meaning focused, but employs various instructional strategies to induce learners to attend to form: although the instructional activities require primary attention to be paid to meaning, they also invite peripheral or periodic attention to linguistic form. One way in which this can occur is through enhanced input—specific linguistic forms (words or grammatical structures) are made prominent in input that learners are asked to comprehend. Prominence can be achieved by highlighting the specific features, using intonation in the case of oral input, or typographically in the case of written input. Another way is simply to ensure that the specific features occur with high frequency in the input. The aim in both cases is to increase the saliency of the features so that they will be noticed by the learners while they are trying to comprehend.

  The second way of inducing attention to form while learners are primarily engaged in communicating is through task-based language teaching (TBLT). In TBLT, learners are asked to perform various types of tasks which create contexts for the interactionally authentic use of language. A task is an instructional activity that satisfies four criteria (R. Ellis 2003): (1) it requires a primary focus on meaning; (2) there is some kind of gap—for example, an information gap that motivates the learners to communicate; (3) learners use their own linguistic resources—i.e. they are not provided with the language needed to perform the task; and (4) there is a communicative outcome—i.e. not just the display of correct language. Learners’ attention to form can be motivated either by the way the task is designed—for example, a task that involves reporting an accident will provide a natural context for the use of the past tense—or by the way the task is implemented—for example, by allowing learners opportunity to plan before they perform the task. As we will see, TBLT has drawn extensively on SLA research and, indeed, has served as one of the main ways of investigating hypotheses in SLA.

  I considered research that investigated memorizing sentences, extensive reading, and text enhancement in Chapter 6 and so will not consider these further here. Instead the main focus of this chapter will be the theory and research that underpins TBLT. The following sections address how tasks have been investigated in SLA and the extent to which TBLT constitutes an effective form of instruction. In the final section of this chapter I consider the relative effectiveness of explicit and implicit instruction.

  Investigating task-based teaching

  The investigation of task-based instruction in SLA has addressed two basic questions:

  What effect do task design and implementation variables have on the way a task is performed?

  What effect does the way in which a task is performed have on L2 acquisition?

  The first question co
ncerns the relationship between (A) and (B) in Figure 11.2. The second question addresses the relationship between (B) and (C). The bulk of the research to date has been directed at the first question. It has examined how task design and implementation variables affect learners’ comprehension of input, the nature of their language production—in terms of CAF—and the nature of the interactions the task gives rise to—in particular, whether any focus-on-form occurs. This research has been cross-sectional: it involves recording learners’ performance of a task and analysing the language use that occurred. Subsequently, on the basis of theory, implications are drawn regarding the effect the performance of the task might have on L2 acquisition. Far fewer studies have investigated the second question, in part because it is difficult to demonstrate that the performance of a single task (or even of several tasks) results in measurable changes in learners’ interlanguage.

  Figure 11.2 Tasks, task performance, and acquisition

  Tasks can be input based or output based. In an input-based task the learner is positioned as a receiver of information and production is not required although it is not prohibited (i.e. learners can elect to speak if they wish to); output-based tasks require production by the learners. Tasks can also be either focused or unfocused. A focused task is designed in such a way as to create a context for the use of some specific linguistic feature—for example, a set of vocabulary items or a particular grammatical structure. An unfocused task has no pre-determined linguistic target and—thus—is designed to elicit general samples of language use. Both focused and unfocused tasks must satisfy the criteria for a task listed earlier. Researchers have investigated all these different types of tasks. Focused tasks—especially of the input-based type—make it much easier to investigate the effects of the instruction on acquisition, as it is possible to design experimental studies that measure whether performing the task resulted in new linguistic knowledge or increased control over partially acquired linguistic forms.