About 4,000 students who took the main SAT college entrance exam last October received incorrectly low scores because of problems with the scanning of their answer sheets.
The College Board, which owns the exam, notified college admissions offices of the mistake and provided the proper scores for affected students in a letter received by some Tuesday afternoon. A College Board spokeswoman, Jennifer Topiel, said students would be notified by e-mail Thursday. Affected students will be refunded their fees from that sitting, the letter said.
Topiel said the "vast majority of students" affected received scores that were within 100 points of their correct score on the three-section, 2,400-point test.
Admissions officials, however, said Tuesday some students had been affected by as much as 130 points — forcing schools to scramble to re-evaluate candidates at a time when many are trying to make final decisions.
"For some this means a scholarship adjustment, for some it means admission to a more selective program within the school," said Jacquelyn Nealon, dean of admissions and financial aid at New York Institute of Technology, where she said between 25 and 50 applicants were affected.
"We'll pull all those folders tomorrow and reach out to any students," she said. "For a school that processes tens of thousands of applications, this is major."
Bruce Poch, vice president and dean of admission at Pomona College in California, where about a half-dozen applicants were affected, said he was told by a College Board official the problem primarily affected a testing site on the East Coast. But Topiel said the students who did not receive credit for some answers were spread around the country.
Fewer than 1 percent of students who took the test in October were affected, Topiel said. All tests from that sitting, as well as from two others, were rescanned.
The investigation was prompted by a routine request for a score verification.
"We immediately launched a thorough investigation into the scoring of that test," she said. "After that investigation, we confirmed that there was a systemic issue."
The letter described the grading problem as a technical issue but Topiel said the College Board was still investigating what went wrong.