You can evaluate a product's effectiveness for your child by asking the right questions. You want the right fit for your child. If the age range doesn't match your child's, he will likely be frustrated if he uses it. Design is key to quality. Children are attracted to a product based on how it plays.
Safety is critically important.
Small parts can be choking hazards for any child under three. Products must be unbreakable and non-toxic. Save your receipts. The store where you make purchases should ensure product safety, but ultimately you are responsible for what your child plays with and how she plays with it. Consider a products durability and versatility.