How robust are models of competence? How stable are competencies across time and across different situations?

For many domains of competence the temporal and situational stability is in the focus of empirical research. It is argued that the analysis of the robustness of competence structure models or competence level models can be investigated in terms of different model components (statistical model parameters or descriptions of proficiency levels) and different units of analysis of statistical inference (e.g., students, classes or populations).