ATLANTA — In a dramatic conclusion to what has been described as the largest cheating scandal in the nation’s history, a jury here on Wednesday convicted 11 educators for their roles in a standardized test cheating scandal that tarnished a major school district’s reputation and raised broader questions about the role of high-stakes testing in American schools.

On their eighth day of deliberations, the jurors convicted 11 of the 12 defendants of racketeering, a felony that carries up to 20 years in prison. Many of the defendants — a mixture of Atlanta public school teachers, testing coordinators and administrators — were also convicted of other charges, such as making false statements, that could add years to their sentences.

Judge Jerry W. Baxter of Fulton County Superior Court ordered most of the educators jailed immediately, and they were led from the courtroom in handcuffs. Judge Baxter, who presided over a trial that began with opening statements more than six months ago, will begin sentencing hearings next week.

“Our entire effort in this case was simply to get our community to stop and take a look at our educational system,” District Attorney Paul L. Howard Jr. said, adding, “I think because of the decision of this jury today that people will stop. I think people will stop, and they will make an assessment of our educational system.”