Background: Little is known about the nature, range and prevalence of different subgroups in language trajectories extant in a population from 4 to 11 years. This hinders strategic targeting and design of interventions, particularly targeting those whose difficulties will likely persist. Methods: Children's language abilities from 4 to 11 years…

This paper uses the Rasch measurement model to analyse data collected on children's attention, activity and impulsiveness at the end of their first year at school by teachers in England, Scotland and Australia. The analysis offers insights into differences in teachers' perceptions of children's behaviour between countries and changes with age. The…