Page 120 - Second language development of newly arrived migrant kindergarteners - Frederike Groothoff

120 Chapter 5 Based on this General Development Model we constructed Figure 5.10, in which both the average development as well as the differences within and between individuals are represented (see Table 2.4 in Appendix 2 for the parameter estimates). The average receptive vocabulary at an age of 73 months was estimated as 7.01. Each month a child grew older, his SS score increased by 0.24, but the quadratic function of age decreased the score by 0.01. 11 10 9 8 7 6 5 4 3 Growth SS Within 80% - Within 80% + Between 80% - Between 80% + Age in Months Figure 5.10: Graphical Representation of the General Development Model of Story Structure with 80% Reliability. Figure 5.10 shows that the effect of Age on SS score is significant; this is a quadratic relation; the increase in SS is larger for younger pupils. The differences within individuals (represented by the striped lines in Figure 5.10) also depend on Age; we can give a more precise estimate of the Story Structure development for older pupils as compared to younger pupils. The differences between individuals (represented by the dotted lines in Figure 5.10) also depend on Age; the differences between younger pupils are larger than differences between older pupils. Exposure to Dutch at School, measured as the number of months a pupil has attended a Dutch school (excluding summer months), was added to the model of SS. A likelihood ratio test showed that the main effect of Exposure to Dutch at School contributed significantly to the fit of the model to the observed data (ΔΧ2 (SS7) = 16.35; df = 1; p < .001; see Table 5.16). The same holds for the interaction between Age and exposure (ΔΧ2 (SS8) = 23.82; df = 1; p < .001). 51 54 57 60 63 66 69 72 75 78 81 84 87 90 93 96 99 102 Story Structure Score