Implicit and explicit language teaching

As we discussed in our section of key terms (section 2.1), implicit teaching is taken to mean a form of instruction whereby a learner is not made aware of what is being taught. This is in contrast to explicit teaching, whereby the learner is made aware of what is being taught. In the English language classroom, implicit teaching might include a task where students interact without any focus on specific language items, in the hope that learners will learn ‗implicitly‘, from the interaction itself. Explicit teaching might include activities which require learners to produce samples of the target language or to discover rules about it.

As we have also noted (section 2.1), declarative knowledge can be defined as ‗knowledge about the features being taught‘ and is normally associated with explicit learning. Procedural knowledge is ‗the ability to use the target features automatically in communication‘ (Ellis 1997: 84), and is normally associated with implicit learning. Explicit teaching and implicit teaching normally endeavour to develop each different type of knowledge. Explicit teaching attempts to develop procedural knowledge and declarative knowledge, whilst implicit teaching attempts to develop only procedural knowledge.

There is a long history of debate in the literature about the different impact of explicit and implicit teaching (see Bialystok, 1982, for an early discussion), often associated with the teaching of grammar but also with the teaching of lexis. This debate has often been associated with the interface and non-interface positions in second language acquisition research. Those who favour explicit teaching tend to be associated with an interface position and those who favour implicit teaching with the non-interface position. The intention here is not to review every study in this area and there is further discussion of form-focused instruction in chapter four. At this stage, we are providing an overview of this area before moving on in the next

section to a discussion of three explicit teaching approaches and how these have been influenced by the Noticing Hypothesis and the Output Hypothesis.

Research investigating implicit teaching is normally associated with Krashen‘s (1981) Input Hypothesis, which we outlined earlier in this literature review. There is some limited evidence to support this hypothesis; namely that it is implicit teaching which contributes to acquisition and explicit teaching can only help learners to monitor their own language use. Krashen offers his own evidence for his hypothesis by describing research which demonstrates that language can be acquired simply through comprehensible input. One recent example is his description of a learner of Hebrew (Krashen 2000) who had no formal explicit instruction in the language. Instead, the learner was exposed to the language over a number of years through his work in a Hebrew speaking environment. He is described as learning in a relaxed way (i.e. not putting himself under pressure) and he does acknowledge some vocabulary correction by colleagues. Based on a recording of a conversation with this learner, four native speakers of Hebrew judged his spoken output to be at least very good and at best equivalent to a native speaker (Krashen 2000:23). The results lead Krashen to conclude:

Armando's case also shows us that one can do quite well in second language

acquisition without living in the country in which the language is spoken and without formal instruction. The crucial variables appear to be comprehensible input and having a good relationship with speakers of the language (Krashen 2000:24).

There has also been some support offered for Krashen‘s views in suggestions that grammar correction (something we would associate with explicit teaching), has only a minor impact on the accuracy of student output. Truscott (1996), for example, suggests that such correction has only a negligible effect on the accuracy of students‘ writing and the most effect when it acts as a monitor.

Early studies which sought to contrast implicit with explicit teaching did not provide conclusive evidence to dispute Krashen‘s findings. An early study by Bialystok (1982), for example, reported on two studies designed to assess how declarative and procedural knowledge may be related. Two sets of learners were given a series of receptive and productive tests to assess their explicit and implicit knowledge of targeted language forms. The results did not

provide conclusive evidence that knowing a form (as demonstrated in a receptive test) ensured that it could be used successfully in a productive test. Bialystok (1982:205) suggests ‗knowing a form, as we have seen, does not ensure that the form will or can be used in appropriate situations when the circumstances change‘. Similarly, Green and Hecht (1992) attempted to assess the relationship between explicit and implicit knowledge by asking three hundred German secondary school learners of intermediate and advanced level to correct grammatical errors in sentences. After correcting the errors, learners were asked to state the rule that had been broken in each case. The findings indicated that learners could correct a high number of the sentences (78%) but could only state the rule which had been broken in approximately half the cases (46%). This suggests that declarative knowledge of language rules did not always directly correlate with procedural knowledge of what was correct. Similar results have also been found in more recent studies contrasting explicit and implicit instruction (for example, Reinders 2005).

Despite these results, there have also recently been a number of studies which have demonstrated the benefits of explicit teaching of grammar or vocabulary. DeKeyser (1995) investigated the difference between explicit-deductive and implicit-inductive instruction on the learning of two rule types (simple categorical and fuzzy prototypical) in an artificial grammar. The results demonstrated that the explicit-deductive group outperformed the implicit-inductive group when expressing the simple categorical rules in new contexts, leading DeKeyser to suggest that production is aided by explicit instruction and practice. These results have been supported by a number of other researchers, who have conducted a variety of studies

investigating the difference between explicit and implicit teaching (for example, Radwan 2005, N.Ellis 2007, Ziemer Andrews 2007, Lingli and Wannaruk 2010). Norris and Ortega (2000, 2001) offer a meta-analysis of large number of similar studies and conclude that, taken as a whole, they demonstrate that explicit teaching does have a greater impact on acquisition of targeted forms than implicit teaching. It must be noted, however, that these results are not entirely conclusive and we can question the manner in which some of the studies tested the impact of explicit teaching. As Ellis (2005) suggests, some studies assume that explicit knowledge can be measured simply by asking learners to state rules and there is a tendency to measure procedural knowledge through the use of restricted tests types such as gap-fill

exercises rather than through free response tests. Discussing vocabulary research, Schmitt (2010:154) argues that researchers need to employ a variety of tests to measure both productive and receptive uses of language and guard against claiming that we can infer one from the other, a suggestion which seems entirely sensible.

Despite these caveats, in this thesis we have broadly accepted the findings about explicit teaching of grammar or lexis and, as a result, our research questions show that this is an investigation concerned with different types of explicit teaching and their impact on the acquisition of DMs. In the next section we will describe the influence of the Noticing and Output Hypotheses on the explicit teaching approaches we will investigate.