This comment completely misses the point. The article's title is "Learnable Programming: Designing a programming system for understanding programs" This is not

This comment completely misses the point. The article's title is "Learnable Programming: Designing a programming system for understanding programs" This is not an article about how to teach or learn programming, this is about creating an environment inside of which learning is made easier. Try giving a freshman a binary search program with an interactive visualization like the ones shown in this article that they can play with, and see if they still struggle with it. Same goes for the permutations. You don't have to teach anything when you can let someone experiment and teach themselves how something works. At the end of the day, true learning always hinges on personal insight, and the best teaching methods are those that make it easiest for a person to extract insight.