Effects Of Input Enhancement And Output Tasks On EFL Learners' Acquisition Of Lexical Chunks

Language input and output were two central issues that have been heatedly discussed in the field of SLA(second language acquisition)because they are vital in promoting L2 learners' interlanguage.Previous studies indicated that input enhancement and output tasks were two potentially effective attention-drawing devices,whereas diverse results were obtained concerning the effects of the two devices.Taken English lexical chunks as target forms and L2 proficiency as an important factor,the current study sets out to explore the following three research questions:(1)What effect does input enhancement exert on the acquisition of lexical chunks by learners of different proficiency levels?(2)What effect do output tasks exert on the acquisition of lexical chunks by learners of different proficiency levels?(3)Is there any difference between the effects of input enhancement and output tasks on the acquisition of lexical chunks by learners of different proficiency levels? If yes,to what extent?The participants of the current study consisted of 173 eight graders that were recruited from a public middle school in Hunan province.The participants were divided into 4 experimental groups and 2 control groups according to their L2 proficiency and the treatment they received: the higher-input enhancement group,the higher-output task group,and the higher-control group;the lower-input enhancement group,the lower-output task group,and the lower-control group.Learners in the input enhancement groups were exposed to textual enhancement,L1 glossing,and input flood;learners in the output task groups were subjected to translation task,sentence reconstruction task and passage reconstruction task.The control groups received none of these interventions.Three language tests were conducted to test learners' gains for target lexical chunks before and after the treatment.Three major findings were concluded from the results and discussions of the current study:(1)Input enhancement exhibited a significant immediate positive effect for learners at both proficiency levels,whereas only higher-level learners achieved prolonged effect.In comparison with the control groups,learners at both proficiency levels failed to show a constant advantage.(2)Output tasks also exhibited a significant instant positive role for learners at both proficiency levels,whereas only higher-level learners' improvement maintained.In comparison with the control groups,only higher-level learners illustrated significant superiority.(3)Regardless of proficiency levels,learners in the output task groups outperformed learners of the input enhancement groups in both the immediate and delayed posttests.And the outperformance was especially prominent for the higher-level output task group.The current study enriched the explorations on language input and output in SLA to some extent.Furthermore,the study provided pedagogical implications for the application of input enhancement and output tasks in classroom instructions.