Learning Japanese as a Second Language: A Processability Perspect ...

any developmental stage—even when they receive instruction in a more advanced developmental stage. This thesis was tested in a classroom study (Pienemann, 1984) in which 10 Italian-speaking GSL children at developmental levels ranging from X to X+2 were instructed to learn structures of X+3. The results showed that only those whose current level was X+2 were able to transfer learnt knowledge into X+3 speech productions; no other children could. This discovery is crucial for language teaching in terms of ‘teachability’ and ‘learnability’. Pienemann argued that ‘instruction 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’ (1988b, p. 60).

On the surface, the ZISA Group’s acquisitional stages appear to be similar to Krashen’s ‘input hypothesis’. However, they have a fundamental difference: The ZISA research group provided an explanation for each stage and the reason behind the ‘processing strategies’ for the move to the next stage, while Krashen did not account for the developmental sequence.

Now we move to an evaluation of the multidimensional model. One of the most important features of the model is the fact that the ZISA Group provided explanations for each stage of the development and processing strategies utilised by the learner. This allows us to understand how and why SLA occurs. In addition, the model is supported by empirical studies. Therefore, this model provides great potential for application to new languages and new areas of research. It is also open to validity testing, which is a crucial issue for any theory. Another important point is its attempt ‘to tie contextual factors, including a range of social and psychological variables, to internal psycho-linguistic processes’ (Larsen-Freeman & Long, 1991, p. 283). In the multidimensional model, the influence of sociolinguistic and psycholinguistic factors on variability in IL is clearly explained. Therefore, the learners’ psychosocial orientation can be predicted from the features observed in the IL.

Pienemann’s (1984, 1988b) teachability theory is especially important in the language-teaching field. The results from the study of the 10 GSL Italian-speaking elementary school children (Pienemann, 1988b) supply empirical evidence for its applicability. Although Pienemann