Mastery motivation is an under-assessed resiliency factor that helps all children achieves their potential; it stimulates the child’s attempt to master tasks that are at least moderately challenging for him or her. Several studies have shown that children were most motivated by tasks that were moderately difficult for them.
Children had lower persistence at tasks that were too hard or perhaps too easy for them. Tasks with moderately difficult for typically-developing peers might be too hard for children with DD. Thus, if we want to have a valid test to measure their mastery motivation, it is important to give children tasks that are moderately difficult for them personally.