Currently we have 2 strategies which have confusing names: "mean of grades" and "simple weighted mean of grades".
Martin suggests the following replacements:
mean of grades -> Mean of percentages
simple weighted mean of grades -> Mean of original values
Here are the definitions of the 2 strategies:
- Mean of grades
- The sum of all grades divided by the total number of grades.
- A1 70/100, A2 20/80, A3 10/10, category max 100:
(0.7 + 0.25 + 1.0)/3 = 0.65 --> 65/100
- The difference from Weighted mean is that weight is calculated as Maximum grade - Minimum grade for each item. 100 point assignment has weight 100, 10 point assignment has weight 10.
- A1 70/100, A2 20/80, A3 10/10, category max 100:
(0.7*100 + 0.25*80 + 1.0*10)/190 = 0.526 --> 52.6/100