If financial aid changes at Princeton, Yale and Stanford attract more students from the middle class, it could potentially have an effect on the prestige of those schools, at least as measured by the rankings experts at U.S. News and World Report.

Robert Morse, who coordinates college rankings for U.S. News, said while he does not take financial aid into account in calculating rankings, he does use many of the potential effects these changes could generate to name America's number one college.

Harvard shares the number one spot with Princeton this year, recovering its top ranking after briefly falling to number two the year before. Yale and Stanford, currently rank third and fifth respectively.

According to Morse, if as a result of increased aid, either the number of applicants or the percent of admitted students who choose to matriculate at these schools-known as the yield-rises, the selectivity rating could go up for Princeton, Yale or Stanford.

Acceptance rate and yield, however, account for only 3.5 percent of the ranking, and so, according to Morse, an increase in these categories would boost school rankings only if all other categories remain the same.

"It's possible...that for the so-called best and the brightest, if they had felt inhibited by the high costs, this will make [Princeton, Yale or Stanford] a more attractive place to go," Morse said. "This could have a positive effect on the ratings."

He added, however, that these changes could take years to be felt, as word of the changes becomes more widely known. He said a more immediate impact might be seen in the magazine's "Best Value" ratings, as the new plans take effect.