To make a presentation more beneficial for your audience it is important to define a specific purpose.
The specific purpose is a one-sentence statement about what you hope to accomplish in your speech.
The specific purpose should be realistic and possible to achieve.
Keep the specific purpose clear and concise.
Once you have written your specific speech purpose, you can decide the main points you want to make, the facts and ideas that best support the main points, and the most appropriate speech outline to follow.
Keep in mind: after your speech, you should test the audience to see if you achieved your specific purpose.