A legal team that has won millions of dollars in the past over errors in standardized testing on Friday served notice that it would file a class action suit against the College Board and Pearson Educational Measurement over errors in scoring October's SAT.

Long-time critics of the SAT said that the lawsuit -- and more that are expected to follow -- could provide new information about how the SAT is scored, how vulnerable the test may be to errors, and how the College Board manages the process. Officials of the College Board and of Pearson, which handles the scoring, declined to comment, citing policies against talking about litigation. The College Board's Web site, however, includes a general statement about the scoring errors and efforts to correct them.

The consequences of the suit could go well beyond the several thousand students whose scores were increased after the errors were found. The suit is also on behalf of all people who took the test -- about 500,000 in all -- because some test-takers received scores that were too high, and the College Board has not corrected those scores. "No one went into the SAT thinking they would have to compete against people with inflated scores," Joseph Snodgrass, a St. Paul, Minn., lawyer who is leading the suit, said in an interview Sunday.

Snodgrass said that there are no plans to sue colleges and that he sees them, like the students, as victims in the case. "The colleges were really put in a difficult position," he said.

But Snodgrass said that he could envision going to colleges -- with information he anticipates gathering during the discovery stages of the suit -- and asking that decisions about both admissions and financial aid be reconsidered.

To that end, he said that he would be seeking access to all kinds of information about how the SAT is scored. "The scope of errors has grown progressively with each press release from the College Board," he said. "We need to peel the onion and find out exactly what is going on. We'll get in there."

In addition, he said that the lawsuit will seek the names (while pledging to protect their privacy) of all affected students. Snodgrass scoffed at the idea that the College Board had fixed the problem by notifying colleges of correct scores, and said that the true extent of damages could only be determined by talking to all of the students. "We need to find out all of the consequences. Did students refuse to apply for scholarships that they might have received? Did they miss admissions deadlines? Did they apply to different colleges? There are all kinds of consequences to this," he said.

Snodgrass and his firm helped a group of Minnesota high school students win millions of dollars from Pearson in 2002 in a settlement over scoring errors on a state-required test. Snodgrass is likely to have company quickly as other firms line up plaintiffs for their own suits, which may later be combined. A California firm that is suing the Educational Testing Service over scoring errors in a teacher-licensing exam is now gathering information about those who received incorrect SAT scores.

The lead plaintiff in the suit Snodgrass is organizing has not been named and has been identified only as a male student who took the SAT in October and who lives in New York State.

Robert Schaeffer, director of the National Center for Fair & Open Testing, said that he spoke to the plaintiff's father and has been providing names of lawyers with experience taking on testing entities to other potential plaintiffs. Schaeffer said he wanted to respect the current plaintiff's privacy and not to provide identifying details about him. But Schaeffer said that the magnitude of the scoring error in his case was "in the middle range" of those affected, agreeing that the scores were off not by either a few hundred points or by 10 or 20. He also said that the student had experienced actual consequences because of the incorrect score.

Schaeffer, whose group has been a leading critic of standardized testing for years, said he thought the coming round of lawsuits had the potential to expose a great deal about the College Board. "This is the suit that will be the tool to get to the bottom of the SAT scoring fiasco," he said.

More broadly, he said that all the adverse publicity about the SAT scoring errors would likely encourage more colleges to drop the SAT as an admissions requirement. In recent weeks, Bennington College has done so and Hamilton College announced that it would make permanent a five-year experiment of not requiring the SAT. Such announcements don't happen without a lot of planning, and Schaeffer said that there are "a bundle more colleges in the pipeline," getting ready for similar changes.

"This is the most significant error the College Board has ever admitted, and the incredibly inept way in which they handled the information has cost them immensely in credibility," Schaeffer said.

Snodgrass, the lawyer suing the board, said it would be easy to show how important the SAT is, and how damaging the errors have been. "While they have tried to downplay the importance of a test score, this is a life-altering test," he said.