It used to be that documents were fixed. The words didn't change, the reader had to follow a single path through the text, and there was no way to change it based on the different needs of different people who might be interacting with it. But today, that's all changed. Interactive or dynamic documents, ones that dynamically respond to their readers, can be found everywhere from sales brochures to pitch decks.
Although it's true that writing a dynamic document comes with its own challenges, it's a far from insurmountable task to build one. Here are some design tips to help you think through what you should do the next time you're creating an interactive document.