To scope a speech you need to narrow dow. what you are talking about into the relevant topic. A easy way to effectivly scope your speech is to ask yourself "what information do I want my audience to know at the end of my speech." Once you've answered his for yourself, use it as your focal point for your speech. Keep what you're talking about relevant to the purpose and thesis of your speech. And make sure to use anything superfluous or extraneous because it will broaden your scope and take the speech away from the ultimate goal.