As if the college admissions process weren't nerve-racking enough, the high school Class of 2006 will have the unique opportunity to carry an additional burden: deciding whether to take the current version of the SAT, the new one being introduced next year -- or both.

The "new SAT" makes its debut in March, revised with tougher reading and math questions and, for the first time, an essay question. The existing test, which became so controversial that University of California leaders said they no longer would use it as an admissions tool, will become obsolete.

It might, therefore, seem axiomatic that this year's 10th-graders would hold off until spring of their junior year to take the new test, and forget about the current version. But many, eager to get a jump on college admissions by taking the SAT early, say the decision isn't so simple.

"It's all really confusing," said Rachel Packer, a 16-year-old sophomore at Sherwood High School in Montgomery County.

For one thing, high school counselors are giving varied opinions to students; Packer said her advisers told her they know so little about the new version that they couldn't offer much help. Test preparation companies are also doling out conflicting advice, and there is no unanimity among colleges and universities either.

Current sophomores at the rigorous New Trier High School in suburban Chicago are being told to take only the new SAT; school official Jim Conroy said he believes most colleges will want scores from the more challenging test. But Michael Soliman, 16, who attends Redlands High School in California, said his counselors persuaded him to plan to take the old and new test, so he signed up for a summer prep course that covers both. "I want to give myself a better chance of getting a higher score," he said.

Officials with the College Board, the nonprofit organization that administers the SAT, are advising students to ask the colleges to which they intend to apply for guidance.

The University of California and the University of Chicago, for example, will take scores only from the new version, starting with students entering in the fall of 2006, as will the University of Virginia. "We want to compare apples with apples and oranges with oranges," said John A. Blackburn, the admissions dean at Virginia.

University of Chicago admissions dean Ted O'Neill said his school wants to avoid students "strategizing and gaming" about which version of the SAT might produce the highest scores.

But Stanford University, Washington University in St. Louis and the University of Denver, among other schools, plan to accept a student's highest individual verbal score and math score from either the old SAT, the new SAT or a combination of the two exams. "We want to provide our applicants with flexibility," said Robin Mamlet, Stanford's admissions dean.

This continues a tradition at Stanford, and many other schools, to consider an applicant's highest verbal and math scores, even if those scores were not earned during the same administration of the test.

The test preparation companies are also divided about which version students should take. The Princeton Review is urging customers to study for and take only the new one, because "students are overtested in general already," said Andy Lutz, the company's vice president for instruction and guidance. Justin Kestler, an executive at SparkNotes, said the old SAT is "like an outmoded car."

Kaplan Inc. (owned by The Washington Post Co.), however, is advising customers to prepare for and take both versions, in part because many students may find the older version easier, said Jon Zeitlin, executive director of pre-college programs. "They should take the time to get their best score," he said.

Some education observers say the firms all stand to gain a financial windfall -- and not just because they get to market new SAT study guides. Leaders in the test-prep industry agree that the new version of the test is more coachable than the old one. The Princeton Review is so confident, Lutz said, that it is raising its guarantee for improvement in scores from 100 points for the old version to 200 points for the new, promising free tutoring for those who don't achieve that goal. "That's why it is sad that a test like this is used in admissions," Lutz said.

Michele Hernandez, founder of Hernandez College Consulting, a firm based in Washington state, said she tells her clients that part of the admissions game is high SAT scores, so it makes sense to take both versions to "have a plethora" of scores to choose from.

But Edward B. Fiske, author of annual best-selling guides to getting into college, said students shortchange themselves if they take the test early in 11th grade, instead of waiting until spring of their junior year. "Why in the world would you want to take the test when you are still academically immature?" he said. " . . . I would never tell anybody to take the old test. The idea that you would get a higher score in the beginning of your junior year is silly."

Fiske and other admissions experts said students should also consider taking the major alternative to the SAT, the ACT, run by a nonprofit organization based in Iowa City.

Robert J. Massa, vice president for enrollment at Dickinson College in Carlisle, Pa., said the ACT and SAT "are looked at the same in the admissions process, which is interesting since they measure different skills." The SAT, he said, has historically been more of a test measuring reasoning -- though the new version, the College Board has said, will be more closely aligned to high school course work. The ACT, which has reading, math, science and English sections, traditionally has been better aligned to high school courses, Massa said.

Most colleges accept both tests, and admissions experts say students should select the one that better suits their strengths.

The ACT is adding an optional writing component in February, and already there is controversy about whether schools will require that students take the writing portion.

It all adds up to more confusion for students. Packer said she and her mother decided that she would take the new SAT, so she signed up for a prep course. But, in the end, she may take both. "It's hard to know exactly what to do," she said.