The most powerful outreach is when you create images in the minds of the audience. An image is processed much faster in the human brain than words. The better you can create a shared image of a certain process or element in the minds of the audience, the more likely you are to succeed in explaining your science.
A shared understanding of basic concepts during your talk will help you explain even the most complex issues. In order to achieve this you must know your audience. How do they view the world? What are their interests? Do they share an experience you can refer to?
It does not have to be images in your slide show. It can just as well be images or concepts that the audience already know, which you then refer to. This is where analogies come on handy as they can help you create an understanding in the audience. If you can create a parallel to soccer or a highway or a snail, they audience will immediately get an image to build on as you go on in you explanation.
Creating images is not only nice for the audience – it also saves time and allows the speaker to focus on the actual message.science-communicator.com