OAKLAND -- The Oakland school district is taking measures to prevent violations in its testing administration after an incident this year left one elementary school without a state Academic Performance Index, or API, score.

School district spokesman Troy Flint said a teacher at Global Family Elementary School failed to cover up or remove 11 or 12 posters and other teaching materials displayed in the classroom, as required by the California Department of Education. Someone reported the problem to district staff members, he said, which led to the investigation.

"There's nothing malicious or intentional about it. It was just an oversight," Flint said.