by Rod Ellis
Table 10.3 Selection of studies investigating effects of explicit instruction
These studies all involved the explicit presentation of the target feature(s). All of them—with the possible exception of Housen et al. (2005)—involved practice activities that included communicative tasks. However, they varied in a number of ways, in particular regarding the length of the instruction provided. The overall results are clear: explicit instruction, together with practice, led to gains over time and to statistically significant differences when the experimental groups were compared to control groups. These gains were evident when the target features involved grammar (Harley 1989; Housen et al. 2005; Akakura 2012), vocabulary (Shintani 2011), a pragmalinguistic feature (Lyster 2004), and pronunciation (Saito and Lyster 2012). In the case of the studies that investigated grammatical features, the gains were evident both in simple features—for example, French negation–and also in more complex features known to cause problems to L2 learners—for example, the contrast between French passé composé and imparfait for French learners of L2 English; English articles for Asian learners; and French passive constructions. Only Akakura failed to find any effect of instruction on one of the features she investigated—generic uses of English articles—but the learners in her study rarely made any attempt to use this feature. One might conclude, therefore, that the type of instruction in these studies—explicit presentation combined with practice that included focus-on-form activities—can result in the development of implicit knowledge or, at least, automatized declarative knowledge.
Those studies in Table 10.3 that were directed at grammar learning reflect the general finding of Norris and Ortega’s (2000) meta-analysis of different types of form-focused instruction, namely that explicit instruction involving Focus-on-Form activities has a large effect on grammar learning.
However, the situation is different for pronunciation. Saito’s (2012) meta-analysis of pronunciation studies reported that while six studies that involved focus-on-form activities reported improvement at a controlled level, only two of them did so at the spontaneous level. All eight studies that involved only focus-on-forms failed to demonstrate any improvement in spontaneous language use.NOTE 2
A number of caveats are also in order. All the studies—with the exception of Shintani’s—investigated learners whose knowledge of the target features was already established. In other words, the studies demonstrate that explicit instruction helps learners achieve greater accuracy in the use of linguistic forms than they have already partially acquired. One might ask whether such instruction is also effective in helping learners acquire completely new linguistic features. Shintani’s study demonstrated that it is effective for teaching new words, which involves item-learning. It does not follow, however, that it is also effective for teaching new grammatical items, which involves system-learning. One interpretation of Akakura’s study is that instruction had no effect on implicit knowledge of a structure—generic articles—which constituted a relatively ‘new’ structure for most of her learners. There is an obvious need to test skill-learning theory in studies that investigate the system-learning of new grammatical structures as DeKeyser (2007) argued that the theory is most clearly applicable to the fairly early stages of learning.
A second caveat concerns how the instruction facilitated learning. In general, the studies were product based—i.e they examined the effects of the instruction in terms of performance on post-tests of various kinds. They did not provide much information about what actually occurred in the ‘black box’ of the classroom—for example, whether and in what ways the learners received corrective feedback. In Chapter 7, we saw that corrective feedback during interaction has been shown to have a positive effect on learning. Saito and Lyster’s (2012) study also showed that the corrective feedback received by one of their experimental groups was crucially important, as only this group showed improvement. Corrective feedback was almost certainly provided in all the studies and this may have been a factor in the effectiveness of the instruction. Later in this chapter, I will return to an examination of the role of corrective feedback.
All the studies provided learners with input including the target feature, often in ways designed to draw attention to the target feature. In other words, these studies examined the joint effect of both input and production practice. This raises another question. Is production-practice needed or does input-based practice by itself suffice? This question is of obvious theoretical importance to SLA, as theories differ in whether they see learning as input- or output-driven or both. I will also examine this issue in a later section of the chapter.
A final issue concerns the nature of the metalinguistic information learners are given in explicit instruction. Norris and Ortega pointed out the lack of consistency across studies in the way in which this is handled. In general, the rules presented to learners are based on pedagogical grammar—i.e. they emphasize ‘clarity’ and ‘simplicity’ over ‘truth’. See Swan (1994) for a list of criteria that pedagogical rules need to satisfy. However, there is considerable variability. Later, I examine a type of explicit instruction that emphasizes the importance of presenting learners with ‘scientific concepts’ about grammar in a way designed to ensure they are internalized. Studies also differ in terms of when the explicit rules were provided—either prior to the instruction or during it. In the next section, I consider instruction where explicit explanations of the target structure occurred within the communicative practice.
Integrated explicit instruction
Whereas PPP takes as its starting point the presentation of explicit information about the target structure, integrated instruction embeds explicit explanation into communicative practice activities. Thus, the difference rests in when the explicit information is provided. The theoretical basis for integrated explicit instruction lies in the Transfer Appropriate Processing Hypothesis, which I introduced in Chapter 8. In accordance with this hypothesis, explicit information will be more effective if it is provided while learners are communicating as they are more likely to remember it and be better able to access it in a subsequent communicative activity.
Spada et al. (2014) reported a study that compared isolated and integrated explicit instruction. Both types of instruction drew on the same topics and themes (e.g. medical practices, famous places) and both involved providing learners with explicit information about the target structure (English passive). In the isolated instruction, the target structure was first explained to the learners who then engaged in communicative/content-based activities without any further explicit focus on the passive. In the integrated instruction, a specific theme was first introduced focusing purely on content. Then, the learners performed the communicative activities during which the teacher provided brief interventions by means of quick explanations and corrective feedback. Learning was assessed by means of a written error-correction test and a picture-cued oral production task. Both types of instruction proved effective and there were no significant group differences. However, the group receiving the isolated instruction gained higher scores for passive on the error-correction test while the integrated instruction group did better on the oral production task.
This study provides further evidence that instruction consisting of an initial explanation of the target structure followed by communicative practice—i.e. isolated instruction—is effective. It indicates, however, that integrated instruction is also effective. While no firm conclusions can be drawn from this study, it points to a differential effect of the two types of instruction. Isolated instruction may contribute mainly to explicit knowledge—the kind of knowledge tapped by the error-correction test—while integrated instruction may be more beneficial for the development of implicit knowledge—the kind of knowledge tapped by the oral production task. As such, it lends some support to the Transfer Appropriate Processing Hypothesis.
Concept-based instruction
As we saw in Chapter 9, sociocultural theory emphasizes the importance of developing ‘concept
ually organized grammatical knowledge’ by means of accounts of grammatical features that explain in detail the link between form and semantic/functional concepts. Such accounts are seen as an important mediational tool. Lantolf (2007) questioned the usefulness of ‘rules-of-thumb’ drawn from pedagogic grammar. He commented ‘rules of thumb are not necessarily wrong, but they generally describe concrete empirical occurrences of the relevant phenomenon in a fairly unsystematic fashion and, as a result, fail to reveal deeper systematic principles’ (p. 36). He argued that learners need access to ‘scientific concepts’, a term taken from Vygotsky (1986). The kind of explicit instruction that Lantolf favours consists of the direct presentation of scientific concepts about grammar followed by activities that provide for spoken and written communicative practice.
Lantolf drew on Gal’perin’s (1989) proposal for systemic-functional instruction. This is based on three fundamental principles: (1) the instruction needs to be organized around coherent theoretical units; (2) it needs to provide a material instantiation of the target concepts; and (3) learners need to verbalize the concept-based explanation to foster full understanding and internalization of the concepts. Principle (1) involves the direct presentation of the ‘scientific concepts’ relevant to the target of the instruction. Principle (2) is achieved by means of charts and diagrams representing the concepts. Principle (3) is seen as crucial—learners need to verbalize the concepts as they perform production activities.
Neguerela and Lantolf (2006) reported a study illustrating this approach. The study investigated 12 students in a typical university Spanish-as-a-foreign-language course. The class met three times a week for 15 weeks. The explicit instruction involved a ‘Schema for the Complete Orienting Basis of Action’ for presenting grammatical aspect. It consisted of a flow chart that led the learners through a series of questions to help them understand when to use the preterite and imperfect tenses in Spanish. The students were asked to verbalize the schema six times while carrying out a number of oral and written activities based on interactive scenarios in which learners argued for their preferred course of action. They then produced a written version of the scenario. The aim was to assist internalization of the information in the schema so the learners could use it automatically when communicating.
The students’ verbal explanations of the grammatical structures were collected at the beginning and end of the course. Initially, these were simplistic and incomplete, reflecting the rules of thumb in in the student textbooks that the students were familiar with. Their explanations at the end of the course—although not always complete—were generally more coherent and accurate, reflecting the complex factors that determine choice of aspectual form in Spanish. Neguerela and Lantolf suggested that this was indicative of internalization of the concept taking place.
The study also provided evidence to show that the learners were able to use the formal features associated with the target concepts more accurately at the end of the course—i.e. their improved conceptual understanding was reflected in improved accuracy in production. However, the effects of the instruction were more clearly evident in students’ written work, which allows for monitoring using explicit knowledge, than in their oral production, which is more likely to draw on their implicit knowledge. Thus, while the study demonstrates that conceptually-organized instruction may help students develop clearer explicit knowledge, it does not convincingly show that the instruction resulted in implicit knowledge of the target featuresNOTE 3.
Neguerela and Lantolf ‘s study can be seen as lending support to the central claim of Sociocultural SLA—namely that learning is mediated by cultural artefacts—i.e. the scientific descriptions of linguistic phenomena presented directly to learners—and by social interaction in the performance of communicative activities. However, the study was not comparative in design and so does not allow us to conclude that giving learners scientific descriptions makes explicit instruction more effective than giving them simplified pedagogical rules. Also, this study and others like it to date have all involved university-level students of foreign languages and doubts must remain about the suitability of Concept-based Instruction for other kinds of learners—for example, young beginner learners or adult learners with low language analytical ability—and in other settings—for example, in second language contexts.
Comprehension-based instruction
So far, I have focused on research that investigated the effects of explicit explanation in combination with production-based practice activities. This reflects the way in which explicit instruction is generally executed. However, as I noted earlier, some cognitive theories of L2 acquisition emphasize the importance of input in learning. Thus, we can ask whether metalinguistic explanation followed by comprehension-based activities—in which learners are induced to process the meaning of the target features in the input—is sufficient for learning to take place and—in fact—whether it is more effective than production-based instruction.
The case for comprehension-based language teaching was first made in the 1960s. Asher (1977) reported the results of a number of studies investigating the effects of his Total Physical Response Method (TPR), which involved learners listening to and responding to commands without any production practice. Overall, TPR proved superior to traditional production-based instruction, although the studies suffered from a number of design problems. In 1981 Winitiz published an edited collection of papers on comprehension-based instruction. In the same decade, Krashen and Terrell (1983) proposed their Natural Approach, which was premised on the assumption that ability to produce in an L2 emerges only after learners have acquired some language through comprehending input. Later, VanPatten (1996) also argued that the acquisition of grammatical features originates in input. However—unlike Winitz and Krashen—he rejected the view that learning will always occur ‘naturally’ and automatically if learners are exposed to comprehensible input and argued that it was necessary to focus learners’ attention on specific grammatical forms and their meanings. The approach he developed—called Processing Instruction—is considered below.
Theoretical positions
Comparative studies of comprehension- and production-based instruction are of theoretical importance in SLA as they provide a means of testing a number of different theoretical positions:
Comprehension-based instruction benefits receptive, but not productive L2 knowledge, whereas production-based instruction benefits productive knowledge, but not receptive knowledge. This position is supported by Skill-Learning Theory which views the effects of instruction as skill-specific (DeKeyser 2007).
Production-based instruction will prove superior to comprehension-based instruction in developing both types of knowledge. This position receives support from theories that emphasize the importance of production in L2 acquisition. The Output Hypothesis (Swain 1985; 1995), for example, proposes that advanced acquisition requires opportunities for pushed output (See Chapter 7).
Comprehension-based instruction will prove superior to production-based instruction in developing both types of knowledge. This is supported by models of L2 acquisition that propose a single knowledge store that is drawn on for both comprehension and production and that develops as a result of processing input. VanPatten (2007) argued that input processing (defined as the process by which a form-meaning connection is established) leads to changes in the learner’s internal grammar, which will be manifest in both reception and production (see Chapter 8).
Production-based instruction will only benefit acquisition if it takes account of the learners’ level of L2 development, but no such constraint exists in the case of comprehension-based instruction. This position is evident in Pienemann’s (1985) claim regarding the learnability and teachability of grammatical structures. Pienemann proposed that the ability to produce a specific grammatical structure depends on whether the learner has mastered the specific processing operation that it requires (see Chapter 4). The Teachability Hypothesis predicts that:
‘ins
truction can only promote language acquisition if the interlanguage is close to the point when the structure to be taught is acquired in the natural setting so that sufficient processing prerequisites are developed’. (Pienemann 1985: 37).
However, this only applies to the acquisition of productive ability. I will examine these different theoretical positions, first by examining studies that compared comprehension-based and production-based instruction and, second by examining studies that investigated a particular type of comprehension-based instruction: Processing Instruction.
Comprehension-based vs production-based studies
Shintani, Li, and Ellis (2013) reported a meta-analysis of studies that have compared the effects of comprehension-based and production-based instruction on L2 learning. Of the 35 studies included in the analysis, 29 involved explicit instruction—i.e. they included an explicit presentation of the target structure catering to intentional language learning. All of these studies measured the effects of instruction using both tests of receptive and productive knowledge. The results for these 29 studies showed that both types of instruction benefitted both receptive and productive knowledge of the target features. Comprehension-based instruction was more effective than production-based instruction for the acquisition of receptive knowledge but only in the immediate tests—i.e. the advantage was not sustained over time. The opposite was the case for production-based instruction: it was more effective than comprehension-based instruction for productive knowledge in the delayed tests, but there was no difference in the immediate tests. The meta-analysis also investigated the relative effects of the two types of instruction depending on the nature of the production-based instruction—i.e. whether it involved focus-on-forms activities or also included focus-on-meaning activities. The comprehension-based instruction was more effective that the production-based instruction for developing receptive knowledge when the latter only consisted of focus-on-forms activities.