The first rule of public speaking is to strictly limit the amount of information you want to present. Decide what main point are absolutely necessary, and then limit your talk to these point. The biggest difference between spoken and written language is that readers can look back over printed works 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 mean that an oral report can’t deliver as much information as a written report. That is, your can’t have as many pieces of information packed into the sane number of works.