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  • 2021OrnumaPhd

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Written Corrective Feedback, Working Memory, and the Development of Explicit and Implicit Knowledge of English Plurals

Research output: ThesisDoctoral Thesis

  • Ornuma Chingchit
Publication date2021
Number of pages335
Awarding Institution
Award date18/10/2021
  • Lancaster University
<mark>Original language</mark>English


Unlike oral corrective feedback that is unanimously well accepted in the second language acquisition (SLA) field as an effective tool that helps promote learners’ acquisition (e.g., Adams, Nuevo and Egi, 2011; Gass and Mackey, 2015), the role of written corrective feedback (WCF) and the extent to which it could help second language (L2) learners develop their second languages are still questionable (e.g., Polio, 2012; Shintani and R. Ellis, 2013). Few attention has also been given to test its long-term effect towards L2 development. Contributing to this gap presented in the literature, the current study examined and compared the effectiveness of direct focused and direct unfocused WCF on the development of Thai EFL learners’ explicit and implicit knowledge of English plurals. Learner differences in working memory capacity (WMC) were also measured in order to explore the extent to which this cognitive factor mediated the effectiveness of WCF.

This study employed a pre-post-delayed posttest design and was carried out over the course of a 9-month period. Seventy-two low intermediate learners were randomly assigned to two experimental groups, one of which received direct focused WCF and one of which received direct unfocused WCF, and a control group which received content feedback. All groups completed batteries of pre, post and delayed posttests, involving an untimed grammatical judgement test (UGJT), a metalinguistic knowledge test (MKT), a timed essay-writing test, and a timed oral elicited imitation test (OEIT). Learner differences in WMC were measured using backward digit span and operation span (OSpan) tasks, all of which were conducted in learners’ first language (L1). In addition, two learners from each group were randomly selected to take part in qualitative interviews to explore potential variables that might mediate the effectiveness of WCF. After the 6-week treatment period, all learners completed exit questionnaire surveys. The delayed posttest was administered three months after the posttest.

The results revealed that direct focused and unfocused WCF provided for the experimental groups and content feedback provided for the control group were equally effective in facilitating the development of learners’ explicit and implicit knowledge of English plurals. Learners’ educational and instructional contexts as well as their proficiency level are posited to have influenced the yielded results. In addition, learner differences in WMC did not moderate the extent to which learners benefited from WCF. Feedback type, instructional context as well as learners’ proficiency level are key factors attributing to the absence of WMC’s moderating effect. A number of theoretical and pedagogical implications are discussed based on these findings.