The first rule of public speaking is a strictly limit the amount information you want to present. Decide what main points are absolutely necessary, then limit your talk to these points. The biggest difference between spoken and written language is that readers can look back over printed words when they don't understand. With spoken language, however, listeners can't go back and check the words. They have to rely on memory. This means that an oral report can't deliver as much information as a written report That is, you can't have as many pieces of information packed into the same number of words.