[gradebook2-dev] GB2 WC Calculation Rationale

[Kohlhepp, Justin]

Hello,
My name is Justin Kohlhepp, and I am a Classroom Support Specialist at American Public University System.

I have a question about why Gradebook2 calculates scores for weighted categories the way that it does. I understand perfectly how the calculations work as they are shown here: https://rsn.rsmart.com/entries/21450036-Gradebook2-FAQ-How-is-course-grade-calculated-for-weighted-categories-.

I have been working on a proposal to alter the way our school's gradebook2 is calculating these grades as I have found that in some cases it can be inaccurate. I was hoping you could possibly shed some light as to why the grades are calculated this way and what the advantages could be. This is specifically in reference to weighted categories where there are items that have not yet been graded. Weighted categories are used across the board at our university, and it is important for us to have accurate grades throughout the course.

In the below (also attached) example, you can see here that there is an item that is only worth 0.5% of the final grade, yet because it is in a category worth 50%, the item is worth 50% because it is the only graded item.

[cid:image001.png at 01CE9DB6.E04CEEB0]

This student has a 50% final grade, but this is certainly not indicative of the student's performance thus far. This student should have a 99%, not a 50%. Is there a reason or any advantage for calculating the grade this way?

I've spoken to a few math professors at our school, and they agree that the student should have a 99% at this point by calculating it this way:

(0.5*(0/100)+50*(100/100))/50.5=.9901, or 99%.

It seems to me that the most accurate way in every scenario to calculate these grades would be to ignore the category weight and just calculate the items on an individual level and then divide by the total percent of the items used.

1. Multiply the (% grade) by the (earned points/total points). Do this for all graded items.
2. Sum up the values found in step #1.
3. Sum up the (% grade) values for all graded items, the same items used for step #1.
4. Divide the sum found in step #2 by the sum found in step #3.

For final grades, once all the items are scored, none of this matters because both methods produce the same results.
If you have any light to shed on this subject, please let me know. I would like to know any possible reasoning behind this method before we submit our proposal for change. It is a difficult issue to search in JIRA, but I tried and was unable to locate anything. Thank you so much.


Sincerely,
Justin Kohlhepp
American Public University System
American Military University  |  American Public University
111 W. Congress St. Charles Town WV, 25443
T 877-468-6268 x3640 | classroomsupport at apus.edu<egain:mailto:classroomsupport at apus.edu> | www.apus.edu<egain:http://www.apus.edu/>


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