You can guide the selection for age appropriateness, but your child will be much more likely to be engaged in the learning opportunity presented by the project if he chooses on his own a project that interests him.
Choosing the right wedding dress entails appropriateness for the type of ceremony you have planned and the right cut for your figure, and must take into consideration the bride's personal taste and preferences.
Age appropriateness - Just because a toddler has progressed past the point of putting everything in his mouth--which he probably did as a baby--doesn't mean that you should throw caution to the wind.
Summer camps have one set of standards, religious organizations may have another, and parents have to decide on a level of appropriateness that is right for their daughters.
Without much appropriateness Elisha has been sometimes described as the "Faust of the Talmud."