Attention spans are changing. It's very noticeable. I am very aware that the kind of books I read in my childhood kids now won't be able to read. I was reading Kipling and PG Wodehouse and Shakespeare at the age of 11. The kind of description and detail I read I would not put in my books. I don't know how much you can fight that because you want children to read. So I pack in excitement and plot and illustrations and have a cliffhanger every chapter. Charles Dickens was doing cliffhangers way back when. But even with all the excitement you have to make children care about the characters.