Writing the introduction for an informative speech is your chance to either grab the audience’s attention, and hopefully maintain it for the duration of the topic, or lose them and have the speech flail off into the land of sleepy crickets. To write a successful introduction, you will be required to have a commanding knowledge of the subject matter and the ability to use words to create a visual aid for the speaker.
Use everything you know
Know your audience. This is important to writing an introduction because depending on the group receiving the speech, the introduction will need to be tailored to their specific understanding. If your introduction is over their heads, you’ll lose them, and if your beginning is too elementary, you’ll lose them as well. For example, you could write about the three different types of Earth-fault boundaries in an introduction to a group of geologists, but you’d only write about the San Andreas Fault to a group of high school students.
Brainstorm for ideas. Think about the subject of the speech and write down several of the most interesting things about it. Include factual elements on the topic that might move the audience emotionally. Write something that will make them sit up in their seats and pay attention to everything that follows. Humor is good. Use it if you can, but remember you are not writing a stand-up comedy routine.
Get the audience involved. Write a question into the introduction that requires the group to participate. Have them raise their hands by asking a "yes" or "no" question. For example, "How many people in this room have used a public restroom?" This question might be perfect for an informative speech on communicable bathroom diseases.
Write in the active voice so the speaker will speak in the active voice. A good example is, "Ted threw the ball." Don’t write, "The ball was thrown by Ted." Use strong and vivid words that will create lasting images in the listener’s minds. Be clear and concise and remember the types of words used to convey an introduction are just as important as how the introduction is delivered by the speaker.
Write the conclusion of the introduction to easily flow into the body of the speech. If the speaker has an easy transition into his speech, the audience will easily follow him into the next topic. Include in the introduction, a list of topics the speaker will be discussing during the rest of the speech.