Caitlin Bruce has been looking for the perfect college to apply to this fall. The New York high school senior has talked to professors and college students, and she has visited several universities. But there's one tool she refuses to use: college rankings.

"It's all so arbitrary," said Bruce, 17. "There are different rankings in different reviews. The fact that colleges are rated differently with each list shows the rankings aren't so wonderful."

Bruce is one of a number of students who are becoming disillusioned with such influential lists, such as the recently published Princeton Review's "Best 351 Colleges" and U.S. News & World Report's "America’s Best Colleges," which for the first time ranked both Harvard and Princeton as No. 1.

Between the rankings’ dramatic changes from year to year on some lists and the lack of student input on others, some students are questioning whether these compilations are reliable sources of information on which to base their choice of higher education.

Such was the case for Northwestern University (search) freshman Shayla Reaves. The 18-year-old became interested in the school after strong recommendations from her guidance counselor, who closely follows college rankings.

But the Illinois school, which was ranked No. 1 in Princeton Review's "The Best Overall Academic Experience" category in 2002, plummeted to No. 17 on the list in 2003.

"I was shocked at the drop," said Reaves, who comes from Jackson, Tenn. "How can a school change so dramatically in one year?"

Northwestern isn’t the only college to be subject to a drastic fluctuation. The University of North Carolina at Chapel Hill (search) dropped out of the top 20 of the Review's “Overall Academic Experience,” after being No. 7 last year. Some of the country's most prestigious schools, including Harvard, Brown and Cornell, also failed to make the top 20.

Still, the rankings remain largely popular, especially among high school seniors and guidance counselors.

U.S. News & World Report’s publication is known to fly off magazine racks. And a week after Princeton Review released its best college lists last year, the rankings were the fourth most searched topic on Google.com, according to Jeanne Krier, publicist for Princeton Review Books (search).

Robert Franek, the leading author of the "Best 351 Colleges," said the schools’ fluctuations are "not surprising" because the rankings are based on student responses to survey questions.

"We make it very clear if a school has slipped, it moves because student opinion does fluctuate," Franek said. "And if they’re not on one list, they might be on several other lists in the book."

Princeton Review editors pick what they consider the top schools – this year there are 351, though there have been fewer in past years – then break them down into top-20 lists for categories such as academics, “Party Schools” and “Greatest College Towns.”

Despite the fluctuations, Franek called Princeton Review's rankings "the best qualitative anecdotal survey" for college-bound students.

While the Princeton Review’s list varies greatly from year to year, the U.S. News & World Report list doesn’t change much. This is because its rankings are based on a formula that combines acceptance rates, freshman retention rates, financial resources and more, instead of student feedback.

Only Vanderbilt University (search) in Tennessee, which was listed in the top 20 national doctoral universities, broke into a new list in 2003.

Lee Stetson, dean of admissions at the University of Pennsylvania (search), said he hopes students looked into U.S. News' rankings more than Princeton Review's. U.S. News ranks U. Penn as the fifth best national university in the nation, while Princeton Review doesn’t rank the school at all in its “Overall Academic Experience” category.

But Stetson said his office pays little attention to college rankings.

"If you take the Ivy League schools and they're not somewhere in the top group in the country, there might be some problem with the criterion," Stetson said. "But I find it difficult for any survey with great specificity to rate anyone that accurately."

Stetson also noted that students should look at more than ratings before they make their college choices. Instead, he suggested prospective freshmen learn as much as they can about the school's academics, as well as its campus life.

Richard Folkers, director of media relations at U.S. News agrees.

"Picking a school based on whether it’s number 1, 12 or 22 just isn't the thing to do," Folkers said. "The idea is students should find the best thing that’s fit for them."