For more than 60 years, the overhead projector has been a favorite presentation tool for educators and business people alike. Its origins in technology go back to the turn of the century, but in the late 1950s and early 1960s, the Minnesota Mining and Manufacturing Company -- 3M -- introduced the use of transparency film for educational purposes and became a major manufacturer of overhead projectors. With the projector's user manual and a little practice time, you'll be ready to give your own presentation.

Two Key Components

Master two key components to effectively use the overhead projector in a presentation environment. The first is to understand how your particular projector works and the second is to gracefully integrate your use of the transparency film with the projector. When this is done well, the overhead projector blends into the background and your audience focuses on the projected images rather than the hardware.

Basic Understanding

Spend time going over the equipment manual in detail and practicing in advance. Learn where the On/Off switch is located and where the lamp is if you need to replace it mid-presentation -- keep a spare bulb on hand for this purpose. Before the presentation begins, tape the electrical cord to the floor for safety reasons and clean the projector glass. Adjust the projector so the image is easily readable and sitting high on the screen to provide all audience members a good view of the information on the screen. Stand at the projector and face the audience during the presentation. Talk to the audience, not to the screen. Stand on one side to minimize distractions caused by your movements.

Overhead Transparencies

When preparing transparencies, use a variety of colors and no more than six bullet points per page. Use large type that is easy to see and read from a distance when it is projected on the screen. Place a piece of paper underneath the first transparency so the screen is blank and dark even when the projector is turned on. Slide the paper to reveal one bullet point at a time. Judge from the audience’s reaction when to move to the next bullet point or topic. Use blank transparencies with multicolored felt tip pens for spontaneous writing and to encourage participation from the audience.

Additional Tips

If a point requires several minutes of discussion, turn off the overhead projector to focus the audience attention on you and away from the screen. Turn the overhead projector back on when you're ready for the next bullet topic. Use this same tactic when you move transparencies across the glass. If the projector is not turned off when you exchange transparencies, a bright light projects on the screen, which causes a distraction. Consider using white borders around the transparencies. These fit around the transparencies and can be purchased in office supply stores. The border provides a place to write notes, and numbering the bordered transparencies keeps the presentation organized. Use a table for the projector that provides enough room for transparencies on both sides of the projector. One side holds the yet-to-be-presented transparencies; the other side holds the completed transparencies. This keeps the presentation flowing smoothly and adds a touch of professionalism.