The role of task sequencing in L2 development as mediated by working memory capacity

Resumen

The present dissertation was inspired by the increasing interest in task sequencing in L2 syllabus design, on the one hand, and the lack of empirical studies, on the other hand, where task sequencing and its effects on L2 development would be theoretically wellgrounded and empirically researched. Moreover, no research has been carried out to investigate the mediating role of working memory capacity (WMC) in L2 development along task sequencing. These considerations became fundamental in the design of the present research. The study has been created based on Robinson’s Cognition Hypothesis (2001a, 2001b, 2003, 2005, 2007b), the SAARC model (2010) and its predictions regarding the effects of task sequencing on L2 acquisition (Robinson, 2005, 2007a, 2010). As for the construct of working memory capacity, Baddeley’s model was adopted for the present work (Baddeley & Hitch, 1974; Baddeley, 2000, 2003). Three pilots preceded the main study, where the operationalization of task complexity was empirically determined, along with the list of target items for L2 students employed in the main part. The experimental design consisted of a pretest, an immediate posttest and a delayed posttest which included a descriptive task and a two-part vocabulary test as two control tasks, as well as a treatment session consisting of input and a series of three tasks manipulated along the +/- spatial reasoning demands. Out of 91 participants who originally participated in the data collection 61 were finally selected to be included in the statistical analyses of the data. All the participants were learners of English as an L2. They represented 4 groups of students: two laboratory groups (English Philology, University of Barcelona) and two classroom groups (School of Modern Languages, University of Barcelona). Participants from each context (laboratory and classroom) underwent two different treatments: a) a task sequence from cognitively simple to cognitively complex along spatial reasoning dimension involved in the task and b) a randomized sequence. Working memory capacity was measured by means of the automated operation span test (Unsworth et al., 2005). The control tests were administered before treatment, immediately after treatment and two weeks after treatment. The results showed that task sequencing (from simple to complex) played a beneficial role in input retention in the case of both the laboratory group and the classroom group. Furthermore, it was found that WMC moderated L2 development independently from task sequencing, but most interestingly WMC was very influential in the results obtained by the target laboratory group that performed treatment with the tasks sequenced from simple to complex. The results are discussed in light of the Robinson’s Cognition Hypothesis (2001a, 2001b, 2003, 2005, 2007b) and the SAARC model of task sequencing (2005, 2007a, 2010, as well as with reference to models of working memory capacity (Baddeley & Hitch, 1974; Baddeley, 2000, 2003) and to some previous studies in applied linguistics on L2 development and WMC and in cognitive psychology on the acquisition of spatial relations.