An article in The Guardian describes a new movement in British publishing of children's and YA books: age banding, The concept, which calls for publisher to mark books as being "appropriate for ages xx-yy," is fiercely opposed by many authors, including J.K. Rowling.

It reminds me of what manufacturers do with toys, an instance for which I can see some justification. If you are a proud auntie shopping for a 6th birthday present for little Emma, you probably have no clue how difficult a game or toy is. Besides, they usually simply list a minimum age and say "and up."

But with a book, it seems to me that kids' reading levels and comprehension levels are so widely divergent, even for a specific age, that this kind of banding is bound to be inaccurate. The proud auntie would be better off asking which authors or genres the child likes—or even simply buying her own childhood favorites—rather than blindly searching for titles based on the child's age.