ST. LOUIS — The proud parents who attended Lincoln Elementary’s honor roll assemblies years ago assumed the school was a shining example of academic achievement.

Children by the dozens lined up to be celebrated for earning grades that put them on the honor roll.

Then the school in St. Charles got state test results.

Most of the students failed, casting doubt on the school’s success and challenging the validity of many of its students’ glowing report cards. Administrators knew they had a problem.

What they did next upended everything parents, teachers and students thought they knew about grading.

St. Charles joined a national movement that — sometimes amid a formidable backlash — is rebuilding how a child’s performance in a class or course is calculated.

It’s a switch that seeks to move away from rewarding students merely for completing work, and instead bases grades on mastery of a subject.

Swept away are points for finished homework assignments, or good behavior and class participation. Instead, grades are more heavily based on exam results and the quality of work.

“There are kids that are good at playing the game of school,” said Julie Williams, principal of Lincoln Elementary, which began to overhaul grading along with other St. Charles elementary schools in 2008. “If you don’t ever do well on tests, but you raise your hand every time, those kids can score well in the traditional system. But when they are tested on a state tests, it exposes the weaknesses.”

New approaches to traditional grading have picked up steam in the last 15 years, an era of accountability on teachers and schools that has more recently focused on individual student growth in learning.