The Study Of The Development Of EFL Learners' Oral Production-Based On Complex Dynamic System Theory

Oral second language research has occupied a central position in the field of applied linguistics.To date,most previous research tends to use product-oriented method by focusing on the relationship with a dependent variable measured at one moment in time usually in the form of averaging group scores and views intra-individual variation as noise,then ignores it.Moreover,few attempts have been conducted to synchronically describe the dynamic developmental traces of complexity,accuracy and fluency(CAF)as dimensions of second language oral production within the same study.What's more,the interactions between CAF subsystems,which may exert an effect on language development,have not been fully considered,not to say being explored.Applied to Second Language Development(SLD),the most important premises of Complex Dynamic System Theory(CDST)see language as a dynamic system,focus on development and variabilities of subsystems(lexis,syntactic etc.)over time,place individual differences at the heart of study,and consider the relationship between CAF dimensions of language proficiency.Therefore,the integration of CDST and CAF may contribute to revealing various developmental patterns of learners' oral L2 production,which provides a comprehensive picture of learners' spoken language development.To investigate how the complexity,accuracy and fluency of oral L2 production develop over time,in the framework of CDST,the present study intended to explore the possibilities of CDST-inspired approaches towards the study of complexity,accuracy and fluency development of ten college Chinese-speaking learners of English,to provide a first attempt to look into the relationship between CAF,to probe into the impact of environmental factors on CAF.Participants performed a topic-given oral narrative once a week over four months.All tasks were digitally recorded and transcribed in CHAT format to be compatible with CHIDLES program software.Using CDST methodologies(like moving min-max graph,moving correlation,Change Point Analysis,Monte Carlos Simulation),the development of complexity,accuracy and fluency over time on the basis of a longitudinal learner corpus consisting of 120 oral samples were analyzed,using thirteen measures targeting various aspects of CAF.The obtained results demonstrate,firstly,some components of complexity and accuracy indeed increased over time(i.e.syntactical complexity,morphological complexity,lexical diversity,grammatical accuracy),whereas lexical sophistication and fluency decreased over time;at the group level the general developmental trends of CAF were fairly linear but at the individual level were rather non-linear with high degrees of variability,indicating that individual learners followed different developmental paths.Critical moments were spotted in the developmental traces of CAF,which testified the variability of oral performance.In other words,new language knowledge and structures emerged with the accumulation of more complex words and syntactic forms being used by learners.Secondly,complex interplays existed between different measures of CAF,and the interactions between them changed over time.A cooperative relationship was found between complexity(syntactical complexity and lexical diversity)and accuracy,a competitive relationship was observed between complexity and fluency,accuracy and fluency.This would indicate that increasing complexity goes hand in hand with increasing accuracy as they develop simultaneously,whereas increasing complexity and accuracy at the expense of decreasing fluency.Finally,individual factors have impacts on the CAF developmental traces of L2 learners.Regional disparity in education could explain to some extent the individual differences in initial state of CAF.The participants who come from developed area such as the eastern and coastal cities of China appear to have better educational resources than the participants from economically underdeveloped area like the central and western regions of China,hence they got higher initial values of CAF.Learning motivation and implicit exposure propel learners' oral L2 production development to move forward over time.Progress has been made for the learners in the aspects of syntactical complexity,lexical diversity and grammatical accuracy over four months.The present study appears to confirm the possibilities and effectiveness of CDST-inspired approaches towards the study of oral L2 production development and have some implications for oral English teaching in China.In the first place,according to the inter-and intra-individual differences observed in this study,individualized learning activities should be designed and put into practice in English oral courses.Then,due to the different development stages of students' oral proficiency and the interactions between CAF,a balanced approach may facilitate efficiency in language teaching practices.Thirdly,integrated vocabulary instruction and opportunities to practice oral language skills are needed,as vocabulary is one of the most difficult aspects for EFL(English as foreign language)learners(in the context of the current study),to help L2 learners in achieving total mastery of new vocabulary.What's more,some tests should be designed to measure how well learners have learned and arouse learners' passion for learning oral language as well.