In light of mixed findings in existing input enhancement research, Issa and Morgan-Short in a 2019 article urged researchers to compare the relative effects of input enhancement that taps into learners’ attention to the external format of second language (L2) target forms (e.g. through capitalizing or boldfacing the forms) and input enhancement that taps into learners’ attention to the internal attributes of L2 target forms (e.g. via increasing the frequency of the forms). In response to this call, the study described in this article drew on a pretest-treatment–posttest-experimental-design to explore whether working memory (WM) capacity modulates the extent to which L2 learners benefit from input enhancement engaged by internal and external attentional manipulations for partially-acquired L2 vocabulary. Analyses of these learners’ lexical gains under different experimental conditions showed that although compound input enhancement engaged by internal attentional manipulations did indeed lead to better lexical gains, such manipulations did not unequivocally lead to greater gains than the external manipulations in all cases. Furthermore, simple input enhancement engaged by internal attentional manipulations (i.e. varying the contextual supports for the target words) could be as effective as compound input enhancement. Importantly, we found that the aforementioned pedagogical effects of internal and external manipulations were both modulated by differences in WM capacity, albeit to differing extents. Insights from this study provide important pedagogical implications for differentiated input enhancement theory and practice.

鉴于现有输入增强研究的混合发现，Issa 和 Morgan-Short 在 2019 年的一篇文章中敦促研究人员比较输入增强的相对影响，这些影响利用学习者对第二语言 (L2) 目标形式（例如通过大写或加粗的形式）和输入增强，以激发学习者对二语目标形式的内部属性的注意力（例如，通过增加形式的频率）。为响应这一呼吁，本文中描述的研究利用了前测-处理-后测-实验设计来探索工作记忆 (WM) 能力是否会调节二语学习者从内部和外部注意力参与的输入增强中受益的程度部分获得的 L2 词汇的操作。对这些学习者在不同实验条件下的词汇增益的分析表明，虽然通过内部注意操作进行的复合输入增强确实导致了更好的词汇增益，但在所有情况下，这种操作并没有明确地导致比外部操作更大的增益。此外，通过内部注意力操作（即改变目标词的上下文支持）进行的简单输入增强可能与复合输入增强一样有效。重要的是，我们发现上述内部和外部操作的教学效果都受到 WM 能力差异的调节，尽管程度不同。这项研究的见解为差异化输入增强理论和实践提供了重要的教学意义。