Setting Letter Grade Scales

The grading scale used to convert overall score to a letter grade is determined by the Gradebook.scale attribute. A scale is simply an ordered mapping from letter grades to thresholds.

If a scale isn’t specified, the default scale (gradelib.scales.DEFAULT_SCALE) is used. This is the “standard” grading scale, where 93-100 is an A, 90-92 is an A-, 87-89 is a B+, etc. An alternative grading scale that “rounds” grades up is also provided (gradelib.scales.ROUND_UP_SCALE), where 92.5-100 is an A, 89.5-92.4 is an A-, 86.5-89.4 is a B+, etc.

Sometimes you might want to find a “robust” scale, where no student is “too close” to a threshold. This can be done with the gradelib.scales.find_robust_scale() function.