There are a couple of different ways to calculate weighted totals in Blackboard.  The following examples will help explain the differences between them.


To Calculate the Weighted Total by Item/Column:


Weighted by Column/Item
Points Possible
Points Earned by Student
Percentage
Homework 1
 A                   25
w                        24
      pA                    10%
Homework 2
B                   20
x                         20
pB                    15%
Paper
C                   50
y                         45
pC                    35%
Final
D                 100
z                         92
pD                    40%
Total Possible Points
                195
                     181
                     100%


Letters were added to these cells to help show the equation.  The equation used to calculate weighted total by column/item:


=((w/A) * pA) + ((x/B) * pB) + ((y/C) * pC) + ((z/D) * pD)


=((24/25) * .1) + ((20/.20) * .15) + ((45/50) * .35) + ((92/100) * .4)


= .096 +  .15 + .315 + .368


= .929 or 92.9%



To Calculate the Weighted Total by Category:


Weighted by Category
Points Possible
Points Earned by Student
Percentage by Category
Homework 1
10
10
Homework 15%
Homework 2
10
8

Homework 3
10
10

Quiz 1
25
23
Quizzes 20%
Quiz 2
25
24

Test 1
50
44
Tests 25%
Test 2
50
47

Discussion Board 1
15
15
Discussion Boards  10%
Discussion Board 2
15
15

Final
200
173
Final 30%
Total
410
369
100%


For each category, that percentage is being spread out across all the items in that category.  Most courses are held in a manner of a running total so Blackboard will only calculate a grade for a submission or columns that have a grade entered.  In this example, we are assuming all assignments have been turned in.


Category
Equation
Percentage Earned
Homework
((10/10) * .05 + ((8/10) * .05) + ((10/10) * .05)
.05 + .04 + .05 = .14%
Quizzes
((23/25) * .1) + ((24/25) * .1)
.092 + .096 = .188%
Tests
((44/50) * .125) + ((47/50) * .125)
.11 + .1175 = .2275%
Discussion Boards
((15/15) * .05) + ((15/15) * .05
.05 + .05 = .1%
Final
(173/200) * .3
.2595%
Total Weighted Grade
.14+.188+.2275+.1+.2595+.915
91.5%


Due to the weights in the categories, the weighted total is a little higher than it would have been if the grade was calculated solely on the total number of points accumulated.  


Total Points - 369/400 = 90%  

Weighted Total = 91.5%


When you have categories of differing values, Equal Weighting converts the columns to percentages and averages the percentages to get the category composite grade. It essentially gives each item equal weight when determining the composite grade. Proportional weighting calculates a category composite grade by adding the raw scores and dividing by the total points possible. It retains the proportional weight of each item, so items with a larger value have more effect on the composite grade.


For example, consider two assignments in a category, one worth 5 points and the other worth 10 points. Assume the student gets 5 points on each assignment.


Equal weighting: 5/5 and 5/10 = (100% + 50%) / 2 = 75% 

Proportional weighting: 5/5 and 5/10 = 10/15 = 66.7%


Canvas works only in proportional grading.


If you have any questions or issues, contact Technology Support Services
419-434-4357
helpdesk@findlay.edu