I know a lawyer who cites psychological research to say that when people hear new, unfamiliar terms, they become so distracted that they are unlikely to pay attention to the next seven words. That's why at trial, any jargon that might be unfamiliar to jurors must be introduced to them with the utmost care. Here's the wrong way:
Q. Doctor, please explain blood flow to the heart?
A. [In a sonorous tone]. Certainly. The heart is actually a double pump forcing blood along a complex network of 60,000 miles of blood vessels, from which oxygen-poor blood arrives from the body and collects through the superior vena cava into the right atrium, an upper chamber of the heart, while at the same time, oxygen-rich blood is flowing from the pulmonary veins into the left atrium (meaning that, as an aside, the pulmonary veins are the only veins in the body carrying oxygen-rich blood), all of which initiates a contraction in the walls of the heart which force blood simultaneously through the tricuspid valve on the right side on the heart -- which is on the left in this diagram -- and the mitral valve on the left -- here in the diagram, on the right -- which then results in the blood collecting in the right and left ventricle before flowing into the pulmonary arteries (right side) and the aorta (left side).
Q. Thank you very much, doctor. And next, let me ask . . .
In stark contract, here's the right way to introduce new terms drawn from the same jury-sensitive lawyer who claims to introduce unfamiliar scientific words in exactly this way:
Q. That's a model of a heart, doctor?
A. Yes, it is. The blood comes in from the rest of the body here, to the right atrium.
Q. Atrium? What's that?
A. That's a chamber of the heart.
Q. You mean like rooms in a house? The first room of the house you enter when you go through the door--that can be an atrium, right?
Q. Same word?
Q. And where does the blood flow after that?
A. The right ventricle.
Q. What's a ventricle?
A. That's the chamber right below the atrium.
Q. Right below that first room in the heart?
Q. And what does the right ventricle do?
A. It pumps the blood towards the lungs.
Q. Oh, so the blood leaves the heart there through the ventricle, which is like a vent? Same type of thing?
A. Same type of thing.
Q. So the right atrium is where the blood is coming in from the body, and the right ventricle is where it's going out to the lungs?
With this method, things move a little more slowly, but in contrast to the first example, the jury is more likely to understand what's happening and can use the new words they are learning as building blocks for understanding more complex concepts.