Naming of aggregation strategies

Naming of aggregation strategies

by Nicolas Connault -
Number of replies: 5
Following a bit of discussion on the MDL-11835 tracker issue, we need to find out what the community prefers in terms of naming of the new gradebook's aggregation strategies.

Currently we have 2 strategies which have confusing names: "mean of grades" and "simple weighted mean of grades".

Martin suggests the following replacements:

mean of grades -> Mean of percentages
simple weighted mean of grades -> Mean of original values

Here are the definitions of the 2 strategies:

Mean of grades
The sum of all grades divided by the total number of grades.
A1 70/100, A2 20/80, A3 10/10, category max 100:
(0.7 + 0.25 + 1.0)/3 = 0.65 --> 65/100
Simple weighted mean
The difference from Weighted mean is that weight is calculated as Maximum grade - Minimum grade for each item. 100 point assignment has weight 100, 10 point assignment has weight 10.
A1 70/100, A2 20/80, A3 10/10, category max 100:
(0.7*100 + 0.25*80 + 1.0*10)/190 = 0.526 --> 52.6/100
What do Moodlers think?
In reply to Nicolas Connault

Re: Naming of aggregation strategies

by A. T. Wyatt -
Oh yes, this caused major discussions from time to time at our place!

Could you just provide a really good help file that clearly explains the difference (as you have written above)? The words we are currently using seem accurate to me, but I agree with you that people don't necessarily realize what they mean in terms of real students' grades. Having a pop up window with examples would have helped me as an instructor. (Having said that, I can't remember what help files are already available on the gradebook screens.)

atw
In reply to Nicolas Connault

Re: Naming of aggregation strategies

by Anthony Borrow -
Picture of Core developers Picture of Plugin developers Picture of Testers
I like ATW's suggestion of having a clear example like the one above readily available. My suggestion is that we use consistent language so that the users will understand the difference. I would avoid the term simple because that which is not simple is complex and actually the math looks more complex in the simple example. I would go with weighted mean and unweighted mean or weighted mean of (scores/grades) and unweighted mean of (scores/grades).

As for some of the language files, it is important that we be consistent.

points = marks - There are three assignments worth 100, 80, and 10 marks/points.
grade = score - A student earns grades/scores of 70%, 25%, and 10% respectively on the assignments.

The student's cumulative average/overall grade depends on whether the relative weight of the number of points/marks are taken into consideration. The weighted mean of the grades/scores is 52.6%. The unweighted mean of the grades/scores is 65%. I would avoid saying the student has 65 or 52.6 points/marks.

That's my 2 cents/pence worth. Peace - Anthony
In reply to Anthony Borrow

Re: Naming of aggregation strategies

by A. T. Wyatt -
Yes, I like those ideas. I think they would help my instructors.

atw
In reply to Nicolas Connault

Re: Naming of aggregation strategies

by Gary Anderson -

What is being proposed as "Mean of original values" is actually computed by hand as (points earned)/(points possible).  So, in the example, it would probably be better understood as (70+20+10)/(100+80+10) = 100/190 = 52.6%.

I have commented extensively on this issue in the Tracker in the past, so I won't repeat those comments.  I will just say that changing the name to "Mean of percents" will be a big improvement and will help those trying to understand the computation, in our experience.  The naming of the other computation seems to require coming to an understanding on the meaning of the terms "grade", "points", "marks", and "values" in different regions of the world, but it seems like the use of "points" may not be understood well outside of the US.

--Gary

In reply to Gary Anderson

Re: Naming of aggregation strategies

by Ray Lawrence -
I've mentioned this in the tracker already, so apologies for repeating it here. It seems to me that the terminology in the default en language pack must reflect terminology that would be applicable to territories where that will be deployed. Terms that are understood/preferred in US should be in the en_us lang pack.