Page 107 - Second language development of newly arrived migrant kindergarteners - Frederike Groothoff

Development of narrative ability 107 The NDW is the first measure of lexical diversity in this study. From the comparison between the consecutive models for the NDW (Table 5.8) it is apparent that a model with a fixed linear component – allowing for differences in Age – fit to the data better than a model with only an intercept (Δχ2 (NDW1) = 79.44; df = 1; p < .001). The variance within (NDW2) or between (NDW3) individuals did not depend on the age of the participants. The inclusion of Age2 (NDW4) did not improve the fit significantly. Hence, in the final model (NDW1) a fixed effect of Age is needed, and with this model we continued the analysis. Table 5.8: Fit of Different Models (-2LL) for Changes in Number of Different Words (168 cases) as well as the Comparison of Consecutive Models. Model NDW0: β0ijcons a 1365.18 Comparison -2LL Models ΔΧ2 Δdf 79.44 1 0.23 1 1.90 2 1.15 1 p <.001 .63nsb .39ns .28ns NDW1: NDW0 + β1Age1ij NDW2: NDW1 + e1ijAge1ij NDW3: NDW2 + u10jAge1ij NDW4: NDW3 + β2Age2ij 1285.75 NDW0 vs NDW1 1285.51 NDW1 vs NDW2 1283.61 NDW2 vs NDW3 1282.47 NDW3 vs NDW4 a NDW 0: In addition to the intercept, variance components for differences within and between individuals are estimated b Only the covariance-coefficient was estimated. Based on this General Development Model we constructed Figure 5.4, in which both the average development as well as the differences within and between individuals are represented (see Table 2.1 in Appendix 2 for the parameter estimates). The average NDW score at an age of 73 months was estimated as 36.27. Each month a pupil grew older the NDW increased by 0.73.