7 Public Speaking Tips From Researchers Who Studied 100,000 Presentations

— -- You don't have to be a "born" public speaker to be a good one, and researchers think they can measure what makes a good or bad presentation.

"This is something you can get better at," one of those researchers, Maegan Stephens, told ABC News. "Sure, there are some people who may be more naturally inclined, but it's a skill you can refine."

Stephens is a specialist in executive communications at Quantified Communications, a company based in Austin, Texas, that has analyzed 100,000 presentations from executives, politicians and keynote speakers. The company says it measures a speaker's words through a transcript with a series of research-based algorithms that were developed in collaboration with Northwestern University's Kellogg School of Management.

The company's data scientists also examine facial expressions, gesture frequency and vocal cues. They then rank speeches on factors like clarity, trustworthiness, confidence and warmth, with the goal of improving a speaker's performance. Their research has produced over 25 different metrics to evaluate a speech.

Here are seven tips from Stephens on improving your public speaking game:

1. The Audience Is the Most Important 'Person'

Stephens said speakers should know what it is the audience needs to know and the constraints, such as time and an audience's background knowledge on a subject matter.

"As a former college lecturer, my job was to say in 90 minutes the most important thing I can tell you today," Stephens said.

2. Content Is Really a Priority

If the content isn’t there, the delivery isn’t going to be at its best, Stephens said, and that can make or break how the message is delivered. The researchers at Quantified Communications found that the language used in corporate earnings calls affects up to 2.5 percent of stock price movement.

"Many presenters speak the way they write -- that is, they use complex sentences with nested clauses and phrases," wrote Stanford Graduate School of Business lecturer Matt Abrahams when reviewing the company's work. "This works well in writing, but when you’re presenting, it’s hard for you to speak and challenging for your audience to follow."

3. Know the Theories of Primacy and Recency

Your audience remembers the first thing they hear and last thing they hear, Stephens said.

"If I give you a 10-minute presentation, research says an audience will most remember the first thing I say and the last thing. They have a hard time remembering the middle," she said.

Stephens said many audiences will form an impression of a speaker within 15 seconds. That means the introduction may be the most important part of your speech, she said.

"It hurts me when a speaker starts with, 'Hi my name is ... and I’m here to talk to you about 'X,'" Stephens said. "You’re missing a key opportunity to get people on board when most likely someone already introduced you. Tell me something I don’t already know. Tell me something that makes me want to listen to you."

4. Build in Rehearsal Time

The best speakers have practiced and set a deadline to finish their speech content, Stephens said. Then they leave a week or any other amount of time to simply practice.