Gradebook

Our default implementation of weighted mean is EXACTLY the same as mean. Because our aggregation coefficient is 1 (weight = 1) the agg method behaves exactly like mean.

Only when changes are made to the weights, does the system behave like a weighted mean system.

Simple weighted mean is not so simple all the time. It can be explained mathematically two different ways. The first way is the total of points divided by the total of possible points (this method assumes the minimum grade is 0). This is the simpler way to figure this out and is as follows:

A1 90/100 Minimum grade 0
A2 70/80 Minimum grade 0
A3 60/90 Minimum grade 0
Category max 100:

((90+70+60)/(100+80+90)) = 220/270 = .8148 = 81.48/100 = 81.48%

The old method dealt with minimum grades (which we've removed as well to simplify things) which confused matters and forced you to use the alternate method of calculating SWM grades which is a PITA.

The more complicated way is as follows and accounts for minimum grades greater than 0:

A1 90/100 Minimum grade 20
A2 70/80 Minimum grade 10
A3 60/90 Minimum grade 30
Category max 100:

((A1-A1_grade_min)+(A2-A2_grade_min)+(A3-A3_grade_min))/((A1_grade_max-A1_grade_min)+( A2_grade_max-A2_grade_min)+( A3_grade_max-A3_grade_min))*100 =
((90-20)+(70-10)+(60-30))/((100-20)+(80-10)+(90-30)) = ((70+60+30)/(80+70+60)) = (160/210) = .7619 = 76.19/100 = 76.19%

Uggh...

We have decided not to confuse the hell out of people and removed minimum from ALL aggregation methods as it makes weighted mean MUCH more fun too.

Weighted mean is not as simple as Simple weighted mean, hence the name. Thankfully Weighted mean can only be explained mathematically one way (probably shooting myself in the foot by saying that here).

A1 90/100 Minimum grade 0 weight 1
A2 70/80 Minimum grade 0 weight 2
A3 60/90 Minimum grade 0 weight 3
Category max 100:

(((((A1-grade_min)/(A1_grade_max-A1_grade_min))*1)+((70/80)*2)+((60/90)*3))/(1+2+3)) = ((.9*1)+(.875*2)+(.6666667*3))/6 = 4.65/6 = .775 = 77.5/100 = 77.5%
((((90/100)*1)+((70/80)*2)+((60/90)*3))/(1+2+3)) = ((.9*1)+(.875*2)+(.6666667*3))/6 = 4.65/6 = .775 = 77.5/100 = 77.5%

The Extra Credit points are added to the category total for all 3 aggregation methods and will not cause any other effect on the category grades.