How do you create a speech on short notice?

If you have very little time to prepare a speech, spend your time zeroing in on your purpose and your audience. Ask yourself, "What do I want to accomplish? How do I want my audience to be different after they have heard what I have to say?"

Instead of focusing on all the things you could say about your topic, focus on what your audience needs to know for you to get your point across. One helpful way to do this is to write down the questions they are likely to have about your topic and then jot down brief answers. You'll find that you've just generated most of the content you'll need for your speech.

What is the ideal length for a presentation?

If by presentation, you mean a speech (not training or workshop) then the ideal length is between 15 and 20 minutes. In the 1970s the U.S. Navy conducted a study to find out how long people can listen to other people talk.

The Navy wanted to find out how to better use the time of instructors and students in the Navy's education system. What they discovered about the ideal length for a presentation surprised a lot of people. It wasn't an hour -- or even a half hour.

The Navy found an audience's ability to focus on what the speaker is saying and then remember what was said drops off significantly at 18 minutes. They found this to be true across the board -- in classroom, presentation, or lecture environments.