読む能力の一次元性とWorking Memory容量 : L2読解テストへ

抄録

This paper reviews the literature and integrates the findings in divisibility/identifiability of L1 and L2 reading skills, and presents a hypothesis concerning L2 reading tests. Whether reading ability can be broken down into component skills is an issue which has long divided reading researchers. Review of the literature reveals what can be almost termed a chaos of results. However, if we distinguish between psychological and psychometric unidimensionality, the apparently conflicting results could converge nicely into a clear picture. That is, reading ability could be considered psychologically multidimensional but psychometrically unidimensional. It may follow that at least for measurement purposes, it is not too unreasonable to treat reading as a unidimensional trait What underlies this virtual unidimensionality of reading ability might be the fact that different levels of reading processes draw on the same cognitive resource, namely, working memory capacity. The capacity theory of comprehension proposed by Just and Carpenter (1992) provides a plausible account for this unidimensionality in the psychometric sense. Since one's working memory capacity is a function of his/her lower-order processing efficiency in their framework, one hypothesis for L2 reading tests would be that for the purpose of revealing individual differences in overall reading ability, we may well concentrate on measuring the reader' s lower-order processing efficiency.