Can you talk a little about how you feel (if at all) that the children's market has changed in the last 20 years or so? Has the bar been raised for authors? I ask because it seems that the recent stuff I read (let's take The Lightning Thief for example) puts a hook in right at the very start - almost the first line of the first page. Older stuff I read (for example The Hero and the Crown) does not have a hook nearly so soon in the book. Have requirements changed? Have kids interests changed? Are there just so many more authors out there now such that this hook is required for agents/editors to get past the first page?
I’m going to have to start this answer by admitting some embarrassing things about myself. Twenty years ago, I was eight. I read Nancy Drew and the Hardy Boys and other old series books put out by the Stratemeyer Syndicate, and that was about it. At ten I moved onto Agatha Christie and read some Sweet Valley Twins and Babysitter’s Club stuff but that was as close to the kid section as I got. Except for the classics and whatever we read in school, I was firmly entrenched in the adult section by the age of 12, and I never looked back. I did not rediscover children’s books until I was 20. So, in the 8 years I’ve been reading children’s books (and in the four years I’ve studied them) not all that much has changed. Kids still want books that interest them and that mirror their lives. Where we used to have protagonists playing in the corn fields, the characters now role play on computers. But the books themselves haven’t changed that much.
That doesn’t mean that children’s books haven’t evolved. For instance, the authorial commentary that CS Lewis delightfully inserts into his Narnia novels cannot be done in today’s books. Partly this is because those kinds of inserts are so darn tricky to achieve. Lemony Snicket does it well in his series, but the authorial comments in The Tale of Desperaux come off condescending towards the reader. In another example, lists are now taboo. Charlotte’s Web has lists of things all over the place especially in descriptions of scenery. That doesn’t happen these days. Lists are boring and are examples of telling not showing. Modern editors and readers don’t tolerate long lists. So, there have been some stylistic changes in children’s books.
But fundamentally, the requirements for a good children’s book have not undergone drastic changes. Good kids books have always had a hook at the beginning. This could be something as dramatic as the call to action experienced in The Lightning Thief or something more simple lime Marmee’s eminent arrival at the beginning of Little Women. As long as there is something of interest that sucks the reader in, a book has a hook. In the examples in the question, the hero is having a sword fight with his gorgon math teacher in Lightning Thief while the hero in The Hero and the Crown wonders who originally told her that her witch mother turned her face to the wall and died when the hero was born a girl. One hook may be more dramatic, but both inspire the curiosity of the reader to keep turning the page. Editors and agents are still looking for that hook because in the end they’re readers too. Just like the end consumer, editors and agents don’t want to keep reading a book if it isn’t catching their interests.