the effects of task complexity on chinese learners’ language production: a synthesis and meta-analysis

the present meta-analysis was conducted to provide a quantitative measure of the overall effects of task complexity on chinese efl learners’ language production. based on the strict inclusion criteria, 12 primary studies were synthesized according to key features. eleven of them were meta-analyzed to investigate effects of raising the resource-directing task complexity. results revealed that (a) there was an assortment of treatments and measures, (b) there was a small to medium positive effect for syntactic complexity (d=0.64) and small effect for lexical complexity (d=0.20), which lends support to the cognition hypothesis there was a small negative effect for accuracy (-0.18) and a close to negative effect (0.01) for fluency in writing, which partly confirms skehan’s trade-off effects, and (c) task modality (oral or written) did not make a significant difference on the overall effects on complexity and accuracy, while make a significant difference on fluency.