...
Of course when we include the ability of instructors to excuse an individual student from an individual item, we discover that P can vary on a student-by-student basis, as shown below:
Fig. 1
Student | Item 1 | Item 2 | Item 3 | Item 4 | Extra Credit Item | S | E | P | % score |
|---|---|---|---|---|---|---|---|---|---|
Joe | 20 | 20 | 20 | excused | 10 | 60 | 10 | 75 | (60+10)/75 = 93.33% |
Melody | 20 | 20 | 20 | 20 | 10 | 80 | 10 | 100 | (80+10)/100 = 90.00% |
...
So under this case, we have the same basic calculation as above, but if we add a student who only completed the extra credit item, we get another non-intuitive case:
Fig. 2
Student | Item 1 | Item 2 | Item 3 | Item 4 | Extra Credit Item | S | E | P | % score |
|---|---|---|---|---|---|---|---|---|---|
Joe | 20 | 20 | 20 | excused | 10 | 60 | 10 | 75 | (60+10)/75 = 93.33% |
Melody | 20 | 20 | 20 | 20 | 10 | 80 | 10 | 100 | (80+10)/100 = 90.00% |
Francis | - | - | - | - | 10 | 0 | 10 | 0 | - |
...
| Note | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Alternative Points-Based Extra Credit CalculationOne way that we could conceivably implement the extra credit calculation would be to revise the calculation above by introducing an additional variable Q = sum of all non-extra credit points possible for scored and unscored items We would then revise the equation as follows: % score = S/P + E/Q In this case, our example above would look like this: Fig 3.
The obvious disadvantage of this strategy is that instructors would not see extra credit points being awarded in the most straightforward common-sense way for students with excused items... so in Dela's case, even though she has been given 10 extra points, giving her 20 out of 20 points for the gradebook, she only receives a 60%, rather than a 100%. |
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So in the table below, the hyphen indicates unscored items, and otherwise a weight is provided to indicate the course grade weight that item will contribute:
Fig. 4
Student | Item 1.1 | Item 1.2 | Item 1.3 | Item 1.4 | Extra Credit Item | Item 2.1 | Item 2.2 | Item 2.3 |
|---|---|---|---|---|---|---|---|---|
Joe | 15% | 15% | 15% | 15% | 6% | 16% | 12% | 12% |
Melody | 20% | 20% | 20% | - | 6% | - | 20% | 20% |
Francis | 60% | - | - | - | 6% | 40% | - | - |
Roderick | 100% | - | - | - | 6% | - | - | - |
...
So, if we were to calculate the "Category 1" grade for Joe, we first need to examine the desired category weights for each item, as in the table below:
Fig. 5
| Item 1.1 | Item 1.2 | Item 1.3 | Item 1.4 | Extra Credit Item |
|---|---|---|---|---|---|
Percent of Category | 25% | 25% | 25% | 25% | 10% |
...