In The Giver (Lowry), Asher, Jonas' friend, is assigned at the Ceremony of Twelve to be the Assistant Director of Education. As with the other assignments, the Elders have been observing Asher his entire life to choose an assignment consistent with his capabilities. And this does seem to be a very good fit.
Asher is clearly a very nice person, whose "'...humor is unfailing'" (Lowry 55). Everyone in the community knows of his "cheerful disposition" (55). When he does something wrong, he promptly apologizes. He seems to be a very active and athletic person, one who does not like sitting still. He must be chastised even at the Ceremony of Twelves "to sit still and face forward" (53). These seem like good qualities for an Assistant Director of Education.
The Elders have also taken note over the years of assignments that Asher would not have been well-suited for because of some problems he has had. As a Three, Asher had difficulty remembering and pronouncing words, so that he confused "smack" and "snack." So, it was clear that Asher would not have been an effective instructor.
Sadly, the Ceremony seems to be an opportunity for the Elders to point out the children's flaws quite publicly. Even though the Chief Elder ends by thanking Asher for his childhood, she has, in front of the entire community, commented extensively on his flaws. Some readers may see this as gentle teasing, but I have always thought this was rather cruel.
It is clear that the children are watched closely and given assignments that reflect their abilities and sometimes perhaps even what they enjoy doing. But I think it would be dreadful to be twelve years old and have my professional fate decided upon for me forever more.