Julia Evans catalogs things to avoid when providing explanations:
This list isn’t meant to make you feel bad about your writing. I’ve probably done all of these things! I’m certainly going to do them again! I even did at least one of them while writing this post!
But knowing that I’m likely to accidentally do these things makes it easier for me to avoid them, and it makes me more receptive to critique when people point out issues with my writing (“Julia, this is assuming a lot of knowledge that I don’t have!“).
Being aware of these patterns also helps me when reading a confusing explanation: “oh, I’m not confused by this explanation because I’m stupid, I’m confused because it’s introduced 6 new-to-me concepts and it hasn’t explained what any of them is yet!“.
Read on for the list and some excellent explanations of what to do and what to avoid when trying to explain things clearly to people.