Instruction and L2 acquisition
One of goals of SLA is to improve language teaching. In this chapter we will consider three branches of this research. The first, do learners learn structures they are taught? The second, do learners learn better if the kind of instruction they receive matches their preferred ways of learning an L2 ? The third, does it help to teach learners how to use the learning strategies employed by good language learners ? In each case , we will consider the main issues involved and sample some of the studies that have been carried out.
A basic assumption underlying the design of most language teaching materials is that there is an inverse relationship between the linguistic complexity of a structure and the ease with which it can be produced and acquired. Second-language (L2) items are therefore presented to the learner in order of increasing linguistic complexity. Research on the acquisition of English L2 grammatical morphology has cast doubt on the validity of such an instructional sequence. It has been shown that the factor most critical to production accuracy is not a morpheme's linguistic complexity, but rather the frequency with which it occurs in the input that the learner receives (Larsen-Freeman 1975, 1976a, b). Unfortunately, morpheme production accuracy in these studies had been measured among learners who had experienced some, if not all, of their L2 exposure outside the classroom. It was possible, therefore, that contributions from input in the wider community overshadowed any effects for explicit instruction.
The following study was conducted, therefore, to compare subjects acquiring English outside the classroom and those learning English in an exclusive classroom environment. It was believed that this research design could shed light on whether classroom input, in which grammatical forms and functions are isolated for presentation, then organized according to gradations of linguistic complexity, affects the development of grammatical morphology in English L2.
This cross-sectional study compared the production of 18 adult native speakers of Spanish acquiring English through either (1) classroom instruction exclusively, (2) input solely from everyday social interaction, or (3) a combination of (1) and (2). Results of the study showed that classroom instruction had a selective effect on the learners' production, accelerating the development of accuracy for linguistically simple plural -s, but retarding the attainment of target-like use for the more linguistically complex progressive -ing. For highly complex grammatical morphology such as article a, instruction appeared to have little impact, as all three groups followed a similar developmental sequence, unaffected by their conditions of exposure to English L2.
Findings of the study suggest that complex areas of target grammar might be excluded from direct instruction in the second-language classroom, so that increased attention can be given to items more responsive to classroom presentation and practice.
What kind of form-focused instruction works best?
1. Input-based instruction vs production-based instruction
Traditionally, grammar teaching has emphasized production. However, some theories of SLA see inter-language driven by input rather than output.
Based on VanPatten and Cadierno’s, form-focused instruction that emphasizes input processing may be very effective. It is proven when they did experimental study. Two groups were given these different instruction. At the end, each group was given a test of production and a test of comprehension. The result was that the group which received the input-based instruction did far better on the comprehension.
It works better because input-based instruction inducing noticing in learning.
2. Consciousness raising
This term refers to attempts to make learners aware of the existence of specific linguistic features in the target language. It can be done by supplying the positive evidence, and the negative one is just the alternative approach.
Based on Trahey and White, the positive evidence works better than the negative one. Their experiment were done to eleven-year-old French learner of English who were given instruction where they were flooded with input containing adverb sentences over two-week period. He wasn’t given any explicit information or negative feedback. After two week, he could show the use of SAVO, Anne quietly watched the television instead using SVAO Anne watched wuietly the television that were wrong.
The positive input in the form of input flooding may help learners to start using some difficult forms, like SAVO
Learner-instruction matching
It is not equally effective if all L2 learners are given the same instructional option in the learning process. The differences of every individual are such factors as learning style and language aptitude are likely to influence which options work best.
Learners with differing kinds of ability may be able to achieve similar levels of success providing that the type of instruction enables them to maximize their strengths. There is some evidence to suggest that this is the case.
It is obviously important to take individual differences into account when investigating the effects of instruction. So, we can see that the good instruction is not always good to use for all L2 learners.
Strategy Training
To developing interlanguage specifically in grammatical structures, we can use the alternative approach that is identifying strategies that are likely to promote acquisition and providing to training in them.
Most of the research on strategy training has focused on vocabulary learning. The result have been mixed . Training students to use strategies that involve different ways of making associations involving target words has generally proved successful.
The idea of strategy training is attractive because it provides as way of helping learners to become autonomous (i.e. of enabling them to take responsibility for their own learning). The main problem is that not enough is known about which strategies and which combinations of strategies work best for L2 acquisition.
