Katie Couric told University of Oklahoma graduates that persistence and the ability to stay connected to friends and family can help a person make an impact on the world.

Speaking at the university's commencement ceremony Friday night, Couric joked about President Bush addressing graduates six days earlier at "a lesser university," in-state rival Oklahoma State University.

She also drew laughs from the crowd of about 15,000 when she said the graduates could call her "Dr. Katie" moments after she received an honorary doctorate degree.

Couric is leaving NBC's "Today" show and in September will become the anchor and managing editor of the "CBS Evening News," a move that will make her the first woman to anchor a network weekday evening newscast alone. She said the coming change means she can better relate to what college graduates are feeling.

"In a funny way, at this moment in time, we're all in the same boat," Couric said. "We're about to step out into the unknown ... Like you, I'm about to leave my comfort zone and step into something completely undiscovered."

Couric recounted how she received her first job in television journalism by persuading a security guard at a network news bureau in Washington to let her call one of the executives, then persuading the executive to let her talk to the bureau chief. Two months later, she said, she got the job.

"Not only do I like spunk, but you've got to have it," she said. "If you don't have it, get it."

Besides being persistent, graduates need to stay connected — to each other and to their friends and family, she said. Couric shared the story of how her husband, Jay Monahan, was diagnosed with colon cancer in April 1997 and died nine months later. Couric has since been an advocate of early cancer screening, and in 2000, she underwent a colonoscopy on the "Today" show.

In the weeks and months afterward, researchers and doctors noted an increase in people who sought early cancer screenings.

"If that is my legacy ... then I have in fact left a small imprint on the world and all of my professional accomplishments pale by comparison," she said.