Your friends may have joked about it for a few days. You certainly read about it in the news. Your parents might have asked you if you knew anyone who went to "that Caltech school."

With the Aug. 30 release of U.S. News & World Report's annual college guide, the college rankings craze that began over a decade ago has continued. There are magazines that evaluate the per-dollar value of your education, there are books that rank graduate schools, and there are top 10 lists of everything from "Best Libraries" to "Best Party Schools."

According to U.S. News & World Report, Harvard, which held the top rank last year, is now the number two school in the country. The California Institute of Technology (Caltech) jumped from number four to number one.

But that doesn't mean you should peel the sticker off the back of your car just yet. According to officials at Harvard and several other schools, numerical rankings such as those in U.S. News & World Report are not an accurate way to compare colleges.

"These simple lists are necessarily very arbitrary," wrote Dean of the Faculty Jeremy R. Knowles in an e-mail message. "The position of a given institution is greatly affected by how the particular calculation 'weights' [various criteria]."

Caltech Provost Stephen R. Koonin says that, while his school appreciates the positive publicity that comes with being ranked number one, he recognizes that the listings cannot be taken at face value.

"It's like using IQ as a measure of intelligence," he says. "It doesn't capture all the factors or all the dimensions of a school."

Administration officials at several schools have recently begun to question to methodology used by U.S. News & World Report and other systems that rank colleges, accusing the magazine of shuffling the rankings each year in order to sell more magazines.

Surveys such as those in U.S. News & World Report consider selectivity, faculty, graduation and retention rates, financial resources and costs, though they often change the relative weightings of these criteria from year to year.