I found this article about “programmed instruction” textbooks on hackaday.
https://hackaday.com/2020/08/28/a-tale-of-tutor-texts/

Essentially it is like a “choose your own adventure “ except instead of choosing whether to go down a magic cave or follow a magic deer, then finding out what the consequences of that choice is, you chooses an answer to a question and get a different response from a “teacher “ who explains why your answer is right or wrong.

I think homeschooling parents would be interested in this.