On Tuesday, Dr. Thaddeus said that key questions remain unanswered about Columbia's data reporting, including which university officials knew about the practice and how long it went on for.
“An arm's-length investigation by an independent body, such as a law firm, should be commissioned without delay,” he said in a statement.
U.S. News & World Report's college rankings are among academia's most-watched lists. Top schools often advertise their ranking and use the list to raise funds or attract high-achieving students. Prospective students have used the list to compare and select schools
Officials at some universities have been caught cheating the rankings system.
A former dean of Temple University's business school, Moshe Porat, was convicted on fraud charges and sentenced earlier this year to 14 months in prison for submitting fake data to bolster the school's M.B.A. rankings. Claremont McKenna College admitted in 2012 that it had reported false SAT scores for years.