Abstract:Abstract:Although syntax is an important dimension in L2 writing research, longitudinal case study and dynamic modeling of its internal indicators are inadequate at present. Based on the Dynamic System Theory, this study examines the internal indicators of syntactic development in L2 argumentative writings by 2 English majors in 4 semesters. With the help of L2SCA and CPA, and by means of visual statistic analysis such as moving min-max graph, moving correlation plot,and supplemented by retrospective interview, the dynamic development trajectories of MLT, DC/T and CN/T are explored, and their dynamic growth models are fitted. The results show that all the three indicators possess the characteristics of variability, interaction, non-linearity and unpredictability during the dynamic development. They are characterized by support, competition, fluctuation, high synergism and individual differences. Change-points analysis indicates that not all indicators develop significantly in stages. The dynamic growth models have verified the developmental trend of observed data, and calculated the growth rate of time series indicators, and scientifically predicted the learners’ maximum language learning potentialities under the ideal circumstances. These findings have certain instructive significance for L2 writing teaching and research.
Key words: dynamic system theory; syntactic development in L2 writing; variability and interaction; dynamic growth model