How do you tell a child skipped pages when you don't have the book's text?

StoryFox launches here on November 11. A child reads an ordinary paper book aloud, and Buk the fox listens: reading speed, expression, then a few questions about the story.

Early on we hit a wall. Most families will never type in or photograph the text of the book they're reading, so there's nothing to compare word by word. And skipping a page or two is the first trick a tired kid tries.

We found a way to spot skipped pages anyway, without the text and without AI guessing. It even gets better with every reading of the same edition.

Before I explain how: parents and teachers, how do you check at home that the reading actually happened?