“…However, despite extensive research on the potential effects of individual differences on L2 learning (see Li, 2017a;Pawlak, 2017, for recent reviews), there are still relatively few studies that have explored the interaction between individual differences and instructional conditions or treatments (e.g., Ando et al, 1992;Tagarelli et al, 2015;Ruiz et al, 2018;Benson and DeKeyser, 2018;Faretta-Stutenberg and Morgan-Short, 2018;Indrarathne and Kormos, 2018;Malone, 2018;Suzuki and DeKeyser, 2017; see Granena and Yilmaz, 2018;Vatz et al, 2013, for reviews). This kind of interactional research (Li, 2017a) examines the extent to which pedagogical treatments are more or less effective depending on learners' personal characteristics or aptitudes, such as personality (Jackson, 2019), learning styles (Grey et al, 2015), language aptitude , working memory (Indrarathne and Kormos, 2018), and declarative memory or procedural memory (Faretta-Stutenberg and Morgan-Short, 2018), to name but a few. Examining these aptitude-treatment interactions (Cronbach and Snow, 1977) will potentially inform the design of pedagogical interventions that can suit learners' characteristics, thereby optimizing L2 teaching and learning.…”