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With the big test coming Saturday, the final SAT prep class was part strategy session, part pep rally. Instructor Cary Wagner ran down the check list of things for students to remember: water, a watch, tissues, a sugary snack.

Then he gave one last tip: try to relax.

Of all the advice during the Kaplan course, that may prove the hardest to follow. Big tests always are nerve-racking but that's especially true this year, with the high-strung world of college admissions buzzing in the wake of revelations that more than 4,000 SAT exams taken last October were given incorrectly low scores.

"There is sort of this fear — what if they score the tests wrong?" said Alexandra Jiang, a high school junior, as she left class last weekend.

Saturday's SAT is the first sitting of the test since the problems came to light. The College Board, which owns the exam, says it is taking several new steps to ensure that none of the problems from last October are repeated: Among them, each exam will be scored twice, by different machines and on different days.

As the prep final class in this high-achieving Boston suburb broke up, students said they did not expect further problems.

But Star Wang isn't taking any chances. She said the error was one reason she decided to take the exam both Saturday and then a second time this spring instead of waiting until the fall for a second try — as most students do.

"You just don't know if it's going to happen again," she said.

Wagner said he never brought up the scoring errors with students during class, though they talked about them during breaks.

"It's not something you really should be anxious about," he said. "But it's going to bring up the anxiety level, particularly of the Type A students."

Pearson Educational Measurement, which scores the SAT exams, has said the mistakes may have been caused by excessive moisture in some answer sheets due to wet weather. Pearson will give answer sheets more time to acclimate after they are delivered to the scanning site, and will use special software to safeguard against errors.

Fewer than 1 percent of the October exams were affected, and most errors were of fewer than 100 points. Colleges say that they were generally able to reevaluate affected applicants' scores before final admissions decisions were sent out.

The bigger worry is that affected students may have been dissuaded from applying to certain colleges in the first place. That's the issue that's more on the minds of current juniors, who will use their scores from Saturday's test to help them narrow down their list of colleges this summer.

"Some of the scores were really, really off," said student Emma Notis-McConarty. If you should have received a 780 on a section of the test and got a 600 instead "you missed out on applying to a whole range of schools."

The errors won't make the job of high school guidance counselors — guiding anxious parents and students through the process — any easier. Some say they will have to think hard about such questions as whether students should request a hand re-score or consider taking other tests like the ACT.

"They're going to ask me a lot of questions, and I need to have answers," said Janet Schneider, director of college counseling at the University School, a college prep school in Nashville, Tenn. She's trying to learn more about the SAT problems before a meeting with juniors and their parents next week.

Some counselors have advised students to request hand re-scores from the College Board; others say that's a mistake unless the score is way off expectations. A hand score costs $50 if no error is found, scanning may well be more accurate, and students could find their scores lowered.

Schneider, like many counselors, says she has some sympathy for the College Board and doesn't want to overreact. On the other hand, she's lost some faith in the system.

"I'm not so worried about this specific incident because it was such a low number, but it does shake my credibility in the grading in years past and years to come," she said.

The errors also have resonated with parents whose children are starting the process.

"If there's anything at all that looks suspicious, I'll definitely have the hand-scoring done," said Norah Webster, a Hingham mother with a daughter in 10th grade who will likely take the exam next year.

That's after her son Cliff, a senior, was recently notified his score on the October exam was 290 points higher than first reported to him. Luckily, he had applied early decision to Bowdoin College in Maine, which does not require SAT scores, and had been admitted without reporting his scores.

"I was furious," Norah Webster said. "It's a stressful time for any parent, going through this whole process, and it was just an added stress we didn't need."

She'll be extra vigilant with her daughter.

"Hopefully by then they'll have it worked out," she said. "There have to be some checks and balances, and hopefully this will be kind of a wake-up call."