Narrative takes the form of a story. Presenters use narratives to support a point that was already made or to introduce a point that will soon be made.
Narratives can be combined with facts or statistics to make them even more compelling.
Storytelling points toward a single goal. Your story should not be forced, but should come across as a natural part of your speech. If your audience thinks you're telling a story just because you read that it was a good idea to do so, your story won't work. The task of a story is to make the audience care. Your narrative should be something that your audience can easily understand and relate to.
Keep it short and sweet. Limit your narrative to three or four minutes at the most. Remember, you are using it to support or clarify your point. Once you've done that, move on. Your story is not there to replace information. It is there to put something you have said into perspective.
The best stories paint a picture. They allow your audience to visualize what you are saying. Make sure your story builds over time and doesn't get boring. Keep your audience interested until the end. Don't overuse stories.
Of course, as the old adage says, "use what you know." Stories are not just about facts— they're also about communicating what you have experienced and what you personally know, and feel, to be true.
Source: Boundless. "How and When to Use Narrative." Boundless Communications Boundless, 3 Mar. 2017. Retrieved 20 May. 2017 from https://www.boundless.com/communications/textbooks/boundless-communications-textbook/supporting-your-ideas-9/using-life-experience-narrative-50/how-and-when-to-use-narrative-201-8004/