The Effects of Processing Instruction and Output-Based Activities on Grammar Learning: The Mediating Role of Working Memory

Processing instruction (PI) is an input-based approach to grammar education based on input processing theory, and output is another element needed for second-language acquisition to be successful. This study sought to examine the impact of PI and output-based activities with the mediating role of working memory (WM) capacity on learning English future tense. To this end, 99 subjects with preintermediate command of English based on an Oxford Placement Test were recruited for the study, and they were divided into three groups: PI, output, and control, with 33 learners in each group. Using a reading-span test, it was revealed that 14 subjects in the PI group, 15 participants in the output group, and 13 learners in the comparison group had low WM, while the rest individuals had high WM capacity. Then, a two-way between-group analysis of variance and a Bonferroni adjustment post hoc test were performed. The results of the analyses showed that both PI and output groups outperformed the control group. Additionally, there was no difference in grammar gain between PI and output groups. Besides, learners with high WM outperformed low WM individuals. The pedagogical implication of this research is that PI and output-based activities can assist teachers in implementing effective strategies to raise L2 learners’ knowledge and consciousness.