Parse, don't validate (2019)

One way I like to use to understand and explain what the author is talking about is IKEA furniture that can only go together one way, the "right" way. People are inevitably going to not look at the manual and just start fiddling, so you design the pieces themselves to reject the wrong combinations.

I don't know if Ikea actually does this, but I just mean as a concept that's one way you can use to imagine it. There are so many examples of this in the wild, for important things, e.g. you can't use the washing machine unless the lid is actually closed all the way.

Sometimes they do, but not always - my roommate once assembled an Ikea bookshelf with one of the panels on backwards.