工作記憶容量大小對於教師操縱第二語學習者注意力與字彙習得效益之研究

Although researchers generally agree that attention is needed for secondlanguage (L2) acquisition, they have not yet reached a consensus on whether the salience of target L2 forms should be enhanced through attention-getting techniques involving learners’ awareness. Meta-analyzing more than 21 extant input enhancement studies, Han, Park, and Combs (2008) attributed the lack of consensus to methodological issues, namely, the lack of distinction between and among the kind of attention invoked in existing studies. In particular, following this view, Issa and Morgan-Short (2018) urged further empirical research that compares the relative effects of input enhancement that taps into learners' attention to the external format of L2 target forms (e.g., boldfacing) and input enhancement that taps into learners’ attention to the internal attributes of L2 target forms (e.g., frequency). The former input enhancement manipulation usually invokes learners’ attention with awareness and the latter usually triggers learners' attention involving little or no awareness. Importantly, while urging researchers to explore the relative effects of the two types of input enhancement techniques—an issue that has only recently been explored in a paper published in Studies in Second Language Acquisition—Issa and Morgan-Short made an a priori claim that individual cognitive differences such as working memory capacity would influence the effectiveness of various external and internal attentional manipulations in input enhancement. To empirically establish Issa and MorganShort' s claim, this study will draw on a long-term (24-week) diachronic time-series research design—a methodological recommendation made by Han et al. (2008)—and will explore whether and how working memory capacity modulates the extent to which L2 learners will benefit from input enhancement treatment implemented with internal and external attentional manipulations for partially acquired L2 vocabulary. Insights obtained from this study will provide important pedagogical implications for differentiated input enhancement theory and practice, whether differentiated input enhancement intervention is needed for L2 learners with different cognitive profiles.