Preparing and Using Visual Aids 220 Speech of the Devil Be sure that any computer-generated graphics are large enough to be seen by the audience. You may wish to enlarge these documents through a computer or overhead projector to be sure that everyone can see them clearly. Diagrams Diagrams are great because they can be made in advance. This means that you can use them when you practice your speech. Diagrams are also inexpensive and easy to transport. As with charts, you can use several different types of diagrams. The diagram can be as simple as an illustration of an object or process, or it can be as sophisticated as a cutaway diagram of an object that shows its internal and external appearance. Three-dimensional diagrams also show an object completely. (These are especially helpful because they help an audience visualize an object most fully.) Flow charts or process diagrams trace the steps in a process. Design and create the types of diagrams that best reinforce your topic. Sometimes the simple dia- gram will be most suitable; other times, a cut-away diagram, three-dimensional diagram, or flow chart will best reinforce your point. The basic rule of thumb: Keep it simple. If you're compulsive, don't worry--just bring a bold-colored marker with you so that you can add more to the diagram as you speak. Do that only if you feel it's necessary, however--and keep in mind that it rarely will be. Films Popular and easy to use, films are well suited to presenting a slice of real life, which makes them a great way to work emotional appeal into a persuasive speech. Films show action, which few other visuals can do. You can prepare your own films or use those already prepared. Stay away from making your own, however, unless you are accomplished in this art; homemade films can look cheesy and can spoil an otherwise polished speech presentation. It's important to check all film equipment before the show, making sure that the volume is properly adjusted. And be sure to watch the film before you use it in your speech. This helps eliminate unpleasant surprises. Flip Charts and Posters Flip charts start with large pads of paper firmly mounted on an easel. To create a flip chart, draw one stage of the process on each sheet of paper. Flip charts are ideally suited to showing the steps of a process: As you deliver your speech, flip from page 1 to page 2, to page 3, and so on. Many speakers take advantage of the fact that you can prepare the entire flip chart ahead of time. Or, you can prepare an outline of the flip chart on the paper, filling in the details with a bold-colored marker as you speak.