fair/equitable/reasonable
Equity, in the educational sense, has sometimes been compared with a golf handicap, being a system which makes it easier for a less skilled/talented/accomplished person to compete with a more skilled/talented/accomplished individual.
By contrast most competitions are run by the philosophy, "May the best one win."
The grading discussed may not seem fair or equal, but may be considered by some to be "equitable." It depends upon what the teacher/school/program is trying to accomplish.
