When should a child move to split sole ballet shoes?

People have various beliefs as to when children should move from full sole to split sole ballet shoes.  Full sole shoes support the foot and provide more resistance, which strengthens the muscles.  It is recommended that all young children start in full sole ballet shoes.  I suggest that children should move to split sole shoes when they begin to wear adult shoe and clothing sizes, graduate from elementary school, or begin pre-pointe level classes.  For many children, these things tend to happen around the same time, at about age 10 or 11.  Waiting until this age ensures the child has muscles developed enough control the structure of split sole shoe.  Also, at this age, children can handle the tighter fit that is necessary for split sole shoes to properly form to the foot and create a more attractive foot shape.