by Rod Ellis
Consciousness-raising Instruction has been shown to be effective in helping learners develop explicit knowledgeNOTE 5. But does this knowledge facilitate the processes involved in subsequent development of implicit knowledge? In fact, this has been little studied. Fotos (1993) showed that the explicit knowledge that learners gained from performing consciousness-raising tasks helped subsequent noticing of the targeted features. Several weeks after the completion of the tasks, the learners in her study completed a number of dictations that included exemplars of the target structures. They were then asked to underline any particular bit of language they had paid special attention to as they did the dictations. Fotos reported that they frequently underlined the structures that had been targeted in the consciousness-raising tasks.
Feedback
Providing learners with feedback is an important element of all the forms of explicit instruction we have examined. Feedback can be positive—i.e. it shows learners their response is correct—or negative—i.e. it shows them their response is incorrect. The nature of the feedback differs in comprehension-based and production-based instruction. In the former, it simply indicates whether learners have succeeded in processing the target feature correctly in the input. In the latter, it enables them to see if they produced the target structure correctly and sometimes provides the correct form.
Somewhat surprisingly, there is little mention of feedback in many of the studies that have investigated comprehension-based instruction. Potentially, the timing of the feedback is significant. It can be provided within a structured input activity—i.e. immediately after learners have responded to an input stimulus—or at the end of the activity—i.e. by the teacher informing the learners of the correct answers for all the stimuli. The former is perhaps more likely to assist input-processing as learners can use the feedback they receive on one item to adjust their response to the following item. In one study that did report feedback procedures (Marsden 2006), feedback was only provided at the end of an activity. In another study (Toth 2006), feedback was provided—sometimes by the teacher and sometimes by learners—on learners’ responses to individual stimuli. No study has investigated the comparative effects of providing feedback in these different ways.
All the different types of corrective feedback I considered in Chapter 7—i.e. input-providing vs output-prompting; implicit vs explicit—can occur in explicit instruction involving production activities. The conclusion I reached in that chapter was that all the types assist learning but that—on balance—the explicit types are more effective than the implicit types. The importance of corrective feedback in explicit instruction is demonstrated in Tomasello and Herron’s (1988) ‘down the garden path’ approach. This involved deliberately eliciting errors in learners’ production and then correcting them explicitly. They found this type of production practice more effective than simply providing learners with explanations of the target structures. The corrective feedback enabled the learners to carry out a cognitive comparison between their own deviant utterances and the correct target-language provided by the teacher.
Saito and Lyster (2012; see Table 10.3) compared the effects of production-based explicit instruction with and without corrective feedback and found that only those learners who received the feedback improved. This suggests that corrective feedback is an essential element in explicit instruction where pronunciation is concerned. Is it possible, then, that corrective feedback by itself suffices for learning to take place—i.e. there is no need for explicit grammar lessons? Spada and Lightbown’s (1993) study suggests this might be the case. In this study, an experimental group received explicit instruction consisting of explicit explanation, focus-on-forms and focus-on-form activities, and corrective feedback. A comparison group did not receive the explicit instruction but the teacher regularly corrected their errors. The experimental group improved accuracy in the use of the target structures. But so too did the control group. This study suggests that as long as learners receive feedback, there may be no need for explicit grammar lessons.
Feedback is viewed as important for acquisition in all theories of L2 acquisition—cognitive and social. It is tempting to conclude that it is the single most important factor in explicit instruction, especially if the feedback is sustained over time. In terms of cognitive theories, it promotes attention to form, it helps learners to carry out a cognitive comparison, and it pushes them to produce the correct form. In terms of social theories, new linguistic forms can emerge in the repair work that occurs in form and accuracy contexts.
The interface positions revisited
The perspective I have adopted in this chapter is to consider research that has investigated explicit instruction in relation to different theories of L2 acquisition. As shown in Table 10.2, these theories (and the types of explicit instruction they lend support to) differ in terms of the interface position they adopt—i.e. a strong or a weak position. I will now reconsider the research in relation to these positions.
The ultimate purpose of all types of explicit instruction is to help learners use the linguistic features targeted by the instruction in unplanned language use without the need for conscious monitoring. Instruction can achieve this directly by facilitating an interface between explicit and implicit knowledge—the strong-interface position—or indirectly by developing explicit knowledge which subsequently, and over time, can promote the usage-based processes involved in the development of implicit knowledge—the weak interface position. Inherent in both positions is the claim that explicit instruction can lead to implicit knowledge and in this respect they differ from the non-interface position. The strong and weak interface positions differ primarily in how and when this is achieved.
In order to investigate these different positions, it is necessary to examine how the learning that results from instruction is measured. That is, separate measures of explicit and implicit knowledge are required. Obtaining such measures is no easy task as language users are likely to draw on whatever knowledge resources they have. However, in R. Ellis (2005c) I proposed a number of criteria for designing tasks that would bias learners to the use of either explicit or implicit knowledge and went on to report a study that investigated the validity of measures of the two types of knowledge based on these criteria. Tasks likely to elicit explicit knowledge are those that focus learners on linguistic correctness and allow them plenty of time to respond—for example, untimed fill-in-the-blank exercises or grammaticality judgements. Tasks more likely to elicit implicit knowledge are those that focus learners’ attention on meaning and are time-pressured—for example, elicited oral imitation tests and oral production tasks. However, if implicit and proceduralized explicit knowledge are functionally equivalent—as suggested by DeKeyser (2003)—the measures I have proposed for implicit knowledge cannot be used to investigate the strong-interface position as currently formulated. Perhaps, though, this does not matter as we can still ask whether explicit instruction results in the type of knowledge (implicit or proceduralized explicit knowledge) needed in spontaneous communication.
The strong-interface position
The studies we have examined in previous sections of this chapter afford mixed evidence. There is little evidence to show that the Processing Instruction studies or the Concept-based Instruction studies resulted in improved accuracy in free oral production tasks—for the simple reason that very few of these studies included such tasks. There is, however, evidence to show that explicit instruction involving focus-on-form activities and corrective feedback does have a positive effect on free oral production. All the studies in Table 10.3 included an oral production task and gains in accuracy were seen in grammatical, lexical, and phonological features. However, there are other studies that have not reported gains. We saw in Saito’s (2012) meta-analysis of pronunciation studies that only two out of six reported positive results. In Ellis (2002b) I reviewed 11 grammar studies that included a measure of free oral or written production. Of these, seven reported improved accuracy as a result o
f the instruction, but four did not.
Is it possible, then, that there a strong-interface for some structures, but not for others? One possibility is that instruction will work if it focuses on a target feature that learners are developmentally ready to acquire. Pienemann (1984) reported a study that indicated this was the case, which led him to formulate his Teachability Hypothesis. However, there is very limited support for this hypothesis. Spada and Lightbown (1999) conducted a study to explicitly test its claims by investigating whether the stage of development that learners had reached in the acquisition of English question forms constrained the effect of the instruction. They reported that the learners followed the sequence of development predicted by Pienemann’s Processability Theory, but that the beneficial effect of the instruction did not depend on the specific developmental stage individual learners had reached. This study, then, did not provide convincing support for the Teachability Hypothesis.
Another possibility is that a strong interface will be found for easy-to-acquire structures. In Ellis (2002b), I suggested that instruction was more likely to result in implicit knowledge of simple morphological features than of complex syntactic features. However, Spada and Tomita (2010) reached the opposite conclusion. They found that explicit instruction directed at those grammatical forms they considered complex—for example, relative clauses—had a larger effect on accuracy in free communication than instruction directed at simple forms—for example, plurals. The problem here is that there are no agreed criteria for determining what constitutes a complex or simple grammatical form. The only conclusion possible at the moment is that explicit instruction can sometimes lead to improved accuracy in oral production for both simple and complex structures.
One other type of evidence can be used to test the strong-interface position and might also help to decide whether explicit instruction results in implicit knowledge or proceduralized explicit knowledge. As we saw in Chapter 8, implicit knowledge resides in the connectionist networks of implicit memory, which—once established—are tenacious and enduring. Explicit knowledge consists of declarative facts in explicit memory and more readily atrophies. We can ask, then, whether explicit instruction results in knowledge that is durable. The results of Norris and Ortega’s (2000) meta-analysis indicated that there was some loss of learning between immediate and delayed post-tests, but that this was relatively small. Some studies (e.g. White 1991), however, have reported substantial loss over time. Whether the effects of instruction are durable may depend on whether learners are subsequently exposed to input containing the target structure and whether they have a communicative need to use it in their own output. One interpretation, then, is that explicit instruction does result in proceduralized explicit knowledge—rather than implicit knowledge—but that implicit knowledge may subsequently develop if the environmental conditions are right. Such an interpretation is more compatible with the weak-interface position.
One important caveat is in order. Just about all the studies examined in this chapter investigated the effects of explicit instruction on features that were already partially acquired. That is, it demonstrated that instruction can lead to greater control—improved accuracy. Arguably, a clearer test of the strong-interface position requires examining whether instruction has any effect on the acquisition of features that learners have no prior knowledge of.
The weak-interface position
It is important to recognize that the weak-interface position does not reject a role for explicit instruction, but rather re-evaluates it. That is, it supports explicit instruction as a means for developing explicit knowledge, which can subsequently be used to facilitate the development of implicit knowledge by tuning attention to form in communicative input and output. Thus—arguably—the weak-interface position supports a lesser but more manageable role for explicit instruction as there is no expectancy that the instruction will lead to immediate implicit or proceduralized explicit knowledge. The weak-interface position assumes that implicit knowledge can only develop naturally through communicative experiences, but that teaching explicit knowledge will help to speed up this process.
What evidence can we cite in support of this claim? Fotos (1993) study showed that teaching explicit knowledge does tune attention to form in subsequent input. We know, too, that learners rely on explicit knowledge to monitor their communicative output, which can then function as auto-input to implicit learning processes (Schmidt and Frota 1986). There are also studies (for example, Spada 1986) that show that learners who have access both to formal instruction and to exposure to English outside the classroom make the greatest gains in proficiency. Spada commented, ‘attention to both form and meaning works best’ (p. 133). An implication of her study is that form-focused instruction functions in conjunction with later communicative experiences. However, all this evidence is indirect. As things currently stand, the case for the weak-interface hypothesis rests more on theoretical arguments than on empirical evidence.
Conclusion
Irrespective of whether the research supports a strong or weak interface position, it is clear that explicit instruction ‘works’ and has durable effects for at least some linguistic features. Its effects are evident in all levels of language—phonological, lexical, grammatical, and pragmatic. Thus Long’s (1983a) early conclusion that ‘there is considerable evidence to indicate that second language instruction does make a difference’ (p. 374) has been borne out by subsequent research.
The focus of this chapter has been on investigating the effects of different kinds of explicit instruction. The following are the tentative conclusions I have reached:
Presentation-practice-production (PPP) instruction results in improved accuracy that is manifest not just in controlled language use but also in free production. Crucial to the effect of this kind of instruction is the presence of activities that cater for the use of the target features under real operating conditions—i.e. communicative language use. Instruction consisting only of pattern practice is unlikely to lead to improved accuracy in free communication.
Instruction that includes an explicit explanation of the target feature is, on the whole, more likely to be effective than instruction that does not—i.e. consists only of practice activities.
Explicit explanation can be provided prior to practice activities as in isolated instruction or during communicative activities as in integrated instruction. The timing of the explicit information may affect the type of knowledge—explicit or implicit—that results, but this awaits fuller investigation.
Further research is needed to investigate the relative effects of presenting learners with simplified explicit explanations of grammatical features or ‘scientific concepts’. The former is typical of the PPP studies; the latter figures in Concept-based Instruction. PPP draws on skill-learning theory and Concept-based Instruction on sociocultural theory. The relative effects of these two types of explicit instruction remain unclear.
Consciousness-raising tasks provide a means of allowing learners to induce explicit knowledge of a grammatical feature, and have been found to be as effective in this respect as giving learners explicit information.
Both comprehension-based and production-based practice activities have been found to be effective. The former contribute mainly to receptive knowledge of the target features and the latter to productive knowledge as predicted by skill-learning theory. However, both types of practice activities contribute to both types of knowledge.
Feedback—especially corrective feedback—plays an important and possibly essential role in the effect that explicit instruction has on learning. Practice activities that do not include feedback—in particular explicit corrective feedback—are less effective than those that do.
The studies investigated in this chapter have been premised on the assumption that explicit instruction works in the same way for all learners. However, this is not always the case. Individual difference factors such as the learners’ age, language aptitude, and working memory are likely
to mediate the effects of instruction. DeKeyser (2007), for example, claimed that high-aptitude learners are more likely to benefit from explicit instruction. Studies that have investigated the mediating role of individual learner factors were considered in Chapter 3.
Notes
1 The non-interface position does not lend support to any form of explicit instruction and so is not considered in this chapter. It is relevant to the following chapter when implicit instruction is considered.
2 Jeon and Kaya (2006) reported a meta-analysis of studies investigating the effects of L2 instruction on pragmatic development. However, the small number of studies precluded any firm conclusion about the effects of explicit instruction when development was measured using natural language data.
3 Lantolf and Thorne (2006: Chapter 11) summarize a number of other studies that have investigated concept-based instruction. None of them, however, showed that the instruction resulted in improvement in free, spontaneous language use.
4 Henshaw (2012) compared groups that received only referential activities, only affective activities, and a mixture of both. All the groups improved on the receptive post-tests. The two groups that completed affective activities were better able to maintain their learning in the delayed tests.
5 However, not all studies have found consciousness-raising instruction effective (see Ellis 2012). While some studies have reported substantial gains in explicit knowledge, others report little. This may reflect the learning difficulty of the target structure. The studies also report considerable individual variation in learners’ ability to benefit from performing CR tasks, suggesting a role for individual difference factors such as language aptitude.