The Granite District proficiency-based grading model is designed around the premise that grades are intended to communicate progress toward mastery of articulated course content standards to students and parents. They are intended to indicate at a prescribed moment in time what a student knows and is able to do with respect to course objectives that have been explicitly taught. They encourage the student to act on feedback and the teacher to adjust and individualize instruction.
Here are a few helpful resources:
Students and Parents Talk About PBG: