5 types of evidence essential for persuasive speeches

Having a dynamic speaker helps, but it takes ammunition—evidence—to really seal the deal. At Ragan Communications’ 2012 Speechwriters Conference last month in Washington, D.C., Rob Friedman, senior director of executive communications at Eli Lilly, listed the five types of evidence that make for truly persuasive speeches.

1. Statistics

“Executives love statistics,” Friedman said. But he warned that they can be “overused, and they can be abused.” You have to choose exactly the right ones to support your claims.

For example, Eli Lilly’s speechmakers often discuss the value of medicine and usually talk about the medical impact. Over the past few years, however, their push has trended more toward economics. A big statistic that executives often pull out is that in Indiana, where Eli Lilly is based, life-science jobs account for 25 percent of job growth over the last decade.

That statement needs context, Friedman said. In this case, that job growth makes up for all of Indiana’s job losses in the automotive sector. “It’s not enough to tell the audience, ‘Here’s the figure,'” he said.