Task-Based Language Teaching (TBLT) was proposed as a foreign language teaching method to help learners gain proficiency in the target language outside the classroom. TBLT differs significantly from other teaching methods in that the syllabus of TBLT is based around tasks that provide goals for learners to master grammar points, while other methods focus on the grammar points themselves. Thus, since TBLT was proposed, scholars have been discussing what kinds of tasks should be used and how these tasks should be sequenced in order to enhance language learning.

Within the research framework of Robinson's Cognition Hypothesis, this paper reviews research regarding the ordering of pedagogical tasks in order to identify those aspects of task sequences that should be examined in the future. The authors argue that tasks should be ordered based on increasing cognitive complexity. After reviewing the existing discussions regarding task order, the relationship between task sequencing and cognitive complexity through the Triadic Componential Framework and the SSARC model are explored. There is little empirical research on task sequences based on the Cognition Hypothesis, since this area of the field is still relatively new. Therefore, by focusing on the order in which tasks are presented to learners in the empirical research on the Cognition Hypothesis and contrasting their results, this paper explores how different sequencing affects language acquisition.