Categorization is one of the main mental processes by which perception and conception develop. Nevertheless, categorization receives little attention with the development of critical thinking in Taiwan elementary schools. Thus, the present study investigates the effect that individual differences have on performing categorization tasks.…

Students are non-randomly assigned, or sorted, into classrooms in various ways across and within schools. In this study, we use longitudinal data sets from three districts to investigate a metric for the characterization of sorting at the school level. We analyze whether non-random student assignment is associated with value-added estimates for…