The more the merrier? A synthesis study of single-coded and dual-coded word learning in theory-driven L2 Chinese instruction

This synthesis study of research trends in single-coded and dual-coded word learning in L2 Chinese instruction utilized 20 studies between 2002 and 2017, which yielded a total of 22 independent samples (N=1,220). Most of the selected studies were guided by Dual Coding Theory and/or Cognitive Load Theory, conducted with L1 English-speaking university learners of novice-level L2 Chinese, and adopted pre- and post-test, between-subjects designs that compared the impacts of different instructional conditions on the participants’ word retention. Its four main conclusions are as follows: (1) For single-character word learning, the dual-coded mode is more effective than the single-coded mode, but it remains unclear which type of dual-coded mode is superior. (2) In two-character word learning, the single-coded mode is more effective for concrete words, and the dual-coded mode more effective for abstract ones. (3) The temporal and spatial presentation of characters, pinyin, and English translation also matter; characters should be presented for a short period before pinyin and English prompts appear; once all three are present, a vertical layout is superior to a horizontal one. And (4) No firm conclusion can be drawn about which is more effective between instructor-guided or student-initiated learning. Discussion of the selected studies’ measurements, items, and learner characteristics is also provided.