This applies only to assignments created before our March release (09-03-2021)
This article explains how students' grades are being calculated when using scale rating criteria. If you want to know more about how to set up grading for your assignment, please read this article on Configurable Grading.
When using scale rating criteria, students are scored on a scale from 1 to 3, 1 to 5, 1 to 7 or 1 to 10. To make sure the lowest score a student can achieve is 0%, we apply a correction to the scale so a received score of 1 is seen as 0%. For example, a 5-point scale can result in 0%, 25%, 50%, 75% or 100%. We will clarify this with some examples.
In the following examples, the student is scored on four criteria by one person (for example, the teacher or one peer).
A student receives the following scores: 2/7, 2/7, 2/10 and 6/10.
This is how their grade will be calculated: ((1/6)+(1/6)+(1/9)+(5/9)) / 4 = 0.25
The grade of the student is 25%.
Another student receives 1/7, 1/7, 1/10 and 1/10.
The grade calculation is: ((0/6)+(0/6)+(0/9)+(0/9)) / 4 = 0
Their grade is 0%
When the student is reviewed by multiple peers, the grade is being calculated based on the average of all points. We take the average received rating per criterion (and not per reviewer) to correct for incomplete reviews and avoid penalising students who get an incomplete review. In the example below, the student is being reviewed by three peers based on the same four criteria as in the previous examples.
Student A is reviewed by student B, C and D.
Criterion 1: student B, C and D gave 4/7, 5/7 and 3/7.
The average score is ((3/6)+(4/6)+(2/6)) / 3 = 0.5
Criterion 2: student B, C and D gave 6/7, 6/7 and 5/7
The average score is: ((5/6)+(5/6)+(4/6)) / 3 = 0.778
Criterion 3: student B and D gave a score of 9/10 and 9/10
The average score is: ((8/9)+(8/9)) / 2 = 0.889
Criterion 4: student B and D gave 8/10 and 6/10
The average score is: ((7/9)+(5/9)) / 2 = 0.667
This results in a total average score of (0.5 + 0.778 + 0.889 + 0.667) / 4 = 0.708
The grade of student A is 70.8%
When you also include other components in the grade, like completing the feedback, this will of course be included in the weighted average. For example, let's say the received ratings count for 80% of the final grade and giving feedback counts for 20%. Student A completed all their feedback and received an average score of 0.708 as in the example above. The final grade of student A will then be 0.708 * 0.8 + 1.0 * 0.2 = 0.767 = 76.7%.
We hope this article clarified how grades are being calculated when using scale rating criteria. If you have any further questions, please don't hesitate to contact us using the blue support button in the bottom left corner of this screen.