Second, professors are disturbed by excessive student worry, challenged by complaints about points lost, and nagged by conscience when assigning borderline final letter grades. Third, recognizing that the system leaves something to be desired, institutions periodically spend inordinate amounts of time attempting to modify the system to make it more fair. By doing this, what we really hope to achieve is letter grades that reflect the original numerical percentage evaluations more accurately. No letter grade will be as fair and accurate as the original percentage grade. By definition, the percentage grade has at least 100 units of assessment, and it typically has 1000 units by including one decimal place, as in my current system.
Fairness demands that there be no QPs and no GPA to magnify student differences.
Some may argue that the GPA is nevertheless acceptable because borderline grades may not make much difference in the long run. With its potential for producing distortion and unnecessary agonizing, the GPA should be discarded and the PPC, or something better, should take its place.