Misunderstanding simple explanations

I firmly believe that a person who truly understands a phenomenon or a process is usually able to explain it in very simple terms, making the explanation accessible to an elementary school student.

You can see a very impressive display of this skill in the Wired “5 Levels” video series. I wish I’d be as cool as one of these experts at explaining things.

There are however two huge misinterpretations of simple explanations. The below is pretty obvious, nevertheless based on some recent conversations I had I thought I’d write this down.

1. Not any simple explanation works.

   The right explanation has to address some of the known facts (otherwise, it’s not an explanation), and not contradict the rest of the known facts (otherwise, it’s wrong). The set of known facts explained is the scope of the explanation.

   Not all explanations have to be exhaustive (i.e. explain all the known facts related to a phenomenon being explained), but all of them have to be realistic (i.e. not contradict any of the known facts at the chosen level of abstraction).

   You can explicitly limit the scope of your explanation, for example you could say that “things can be only in one place at a time”, but clarify that you are talking about things that are not very small.

   You can also choose the level of abstraction when you are explaining things, for example in this video a neuroscientist explains what a connectome is. To a 13-year-old he says that “cells in your brain are connected by wires”. While the cells are not really connected by wires, the explanation works, because at the chosen level of abstraction it’s important that the cells are connected and can transmit signals to each other.

2. Simplified explanations still have to use fact language. You can simplify different things.

   The right explanations would show the underlying logic behind the process being explained. The wrong explanations would introduce simplified moral categories like “good” or “bad”.

   It’s not that you can’t use words like “good” or “bad”, but you can’t reduce complex subjects to simple moral categories.

   Some examples:

   • “Vegetables are good for your health, but vegetables alone may not be enough”. “Good” works well.
   • “Killing people is bad”. “Bad” does not work well in this explanation. It’s not that killing people is good, it’s rather that there are a lot of exceptions to the rule. Are soldiers defending their country “bad”? Is a police agent who shot an armed criminal who was about to kill hostages “bad”? An explanation relying on this statement is at risk of being misinterpreted and miss the mark.

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