OMAHA, Neb. (AP) — Omaha Public Schools is testing a new grading scale that makes it harder to pass a class.

About 12,000 elementary, middle and high school students across all schools in the district will participate in the field test.

The new grading scale is the latest round of changes to the district’s standards-based grading system, which has been tweaked several times since a shaky rollout in 2010 confused teachers, parents and students.

The district has sent letters home and emailed all families in the district as well as compiled brochures, videos and other materials.

Staff, parents and students will be able to provide feedback throughout the semester that could determine whether Omaha Public Schools decides to adopt the adjusted grading scale districtwide for the 2017-2018 school year.