Chapter 10 presents discussion of the results obtained in the case study, followed by limitations of the study. The results of the case study partly align with previous research findings in CDST. On the one hand, the study provided support for complex, dynamic, and non-linear development of syntactic complexity, lexical complexity, accuracy, and fluency (CALF) in L2 writing in the case of individual learners. It also provided some evidence for multiple interactions between CALF variables, intermittent periods of stability and variability, and varying rates of growth of these variables. Most importantly, the case study showed a positive relationship between intra-individual variability and the rate of language development in L2 writing at secondary school. On the other hand, however, the case study did not provide sufficient support for the claim that language learners follow different developmental paths. More precisely, it showed that the individual learners’ learning trajectories were qualitatively unique, but that they rarely differed from the group in statistically significant ways. Although there was some substantial intra-individual variability and inter-individual variation, the learners were not so different after all. The main limitations of the case study are that it focused on a limited number of participants and revealed idiosyncratic research findings.