Good advice on communicating about science from the 4gravitons blog:
If there’s one thing the Center for Communicating Science drummed into me at Stony Brook, it’s to be careful with words. You can teach your audience new words, but only a few: effectively, you have a vocabulary budget.
Sometimes, the risk is that your audience will misunderstand you. If you’re a biologist who talks about treating disease in a model, be careful: the public is more likely to think of mannequins than mice. . . .
[N]obody is going to misunderstand “pupillary response”. Nonetheless, that chain of reasoning? It takes time, and it takes effort. People do have to stop and think, if only for a moment, to know what you mean.
That adds up. Every time your audience has to take a moment to think back and figure out what you just said? That eats into your vocabulary budget. Enough moments like that, and your audience won’t have the energy to follow what you’re saying: you’ll lose them.
We don’t need to dumb things down to be understood. (Or not very much anyway.) We do need to be careful with our words. Use our vocabulary budget sparingly, and we can really teach people. Spend it too fast…and we lose them.
I would add that the same principle applies to any technical field and even to science fiction and fantasy writing. A small sprinkling of specialized vocabulary words can convey authenticity and the flavor of what you are writing about, without exhausting your "vocabulary budget" and wearing out the audience.
If you talk about a technical subject to lay persons often, develop a standard repertoire of substitutes for technical vocabulary, and of non-technical but accurate descriptions of technical concepts.