The White House is running short on time to accomplish its goal of encouraging more experimentation with competency-based education and new accreditation pathways. So the Obama administration’s Department of Education this week tapped a seasoned university president for help. Paul LeBlanc, who leads Southern New Hampshire University, will begin a three-month appointment at the department next week. He will be a senior adviser to Ted Mitchell, the under secretary. “It’s an exciting opportunity to be part of the conversation,” said LeBlanc, who has led Southern New Hampshire for a decade and will return to the university at the end of May.