Thousands of Minnesota students who were wrongly failed on a required math exam will be allowed to sue the testing company in a class-action lawsuit, a judge has ruled.

In a June 4 order distributed to attorneys, Hennepin County District Court Judge Allen Oleisky approved a request by some affected students to sue as one instead of bringing their claims against National Computer Systems Inc. (NCS) individually.

NCS, now known as NCS Pearson, wrongly scored thousands of math tests last year. Nearly 8,000 Minnesota students in eighth through 12th grades incorrectly received failing grades because the company used the wrong “correct” answers to score six questions. Some students were denied diplomas as a result.

NCS Pearson hoped that each case would be handled separately, arguing that the level and type of injury done to each student was different. But Oleisky disagreed. “In this case, common questions of law and fact exist between the members of the putative class,” he wrote in his 12-page order.

Shawn Raiter, an attorney representing dozens of students, said the ruling is significant. “It allows us to litigate this case once, it allows us to use the strength in numbers, and it is really quite efficient,” he said. Raiter said some students and their families might have been less inclined to seek legal remedy if they had to go it alone.

NCS Pearson has offered to cover all “legally cognizable out-of-pocket” expenses for its error on 47,000 exams. That includes tutoring, books, mileage related to special classes, and lost wages. The company also extended a $1,000 tuition voucher to some affected students.

In an unrelated decision, Florida Education Commissioner Charlie Crist said he would not automatically renew the state’s multimillion-dollar contract with NCS Pearson, which scores the state’s Comprehensive Assessment Test. A state education department spokeswoman cited problems with the company’s service–including delays in the reporting of scores last year–as one reason the state will reopen bidding on the contract.