A Case Study On The Effect Of The POA On Linguistic Complexity Of English Writing By The Students At Different Proficiency Levels

Based on the theory of the Production-oriented Approach(POA),a 16-week longitudinal study(including nine weeks of teaching experiment)was conducted,using mixed methods,on six freshmen majoring in Marine Engineering in Dalian Maritime University.Altogether,72 writing samples were collected.This study is intended to explore how the POA affects syntactic complexity and lexical complexity of English writing by the six participants.The LCA and L2SCA are used to measure syntactic complexity and lexical complexity quantitatively.Semi-structured interviews,focus group and classroom observations are adopted to discuss the reasons.Results are as follows.(1)Generally,the indices of MLT and CN/T display significant differences between higher level and lower level,namely,the POA exerts the greatest impact on the higher-level participants in terms of syntactic complexity.As for lexical complexity,the indices of LV show significant differences between higher level and lower level and between higher level and intermediate level,which indicates that the POA brings out the greatest impact on higher-level students.(2)For higher-level learners,the indices of LV demonstrate significant difference between pretest and delayed posttest,showing that the POA has the most significant effect on lexical complexity of students'written language,among which the enabling phase brings out a powerful effect on them.(3)For intermediate-level learners,based on the indices of MLT,CN/T,NDW and LV,the values of posttests are higher than those of pretest,which displays that the POA exerts positive effect on linguistic complexity.The assessing phase and enabling phase play a more positive role.(4)For lower-level learners,the indices of CN/T exist significant difference between pretest and delayed posttest,revealing that the POA has a significant impact on syntactic complexity of students' written language,and the enabling phase has a more positive effect.From the theoretical perspective,the present research is intended to provide more empirical data for the studies of the POA to verify its effectiveness,and to offer a new study perspective as well.From the pedagogical perspective,the study offers cases to English teachers in order that they can teach more effectively by using the POA.Meanwhile,in the process of using the POA,teachers can pay more attention to individual differences,especially the differences of students at different English proficiency levels.