crucible

I was reading a book about communication published by Harvard Business Review. The book says there are 4 steps to persuade others. One of the step is to present evidence. The author suggests that you should present vivid evidence.

When I learn new vocabularies, I found that some words are easy to remember, some aren't. Words that create mental pictures are easier to understand and remember. Take the word crucible for example. One definition is a difficult test or challenge. This definition is abstract and hard to imagine. However, another definition a pot in which metals or other substances are heated to a very high temperature or melted is better because it has a physical object "pot" in it. The best of all is this

Now the "difficult test or challenge" is easier to memorize. When you are put in a crucible, you are under a difficult or challenge.

A picture is worth a thousand words, isn't it?