Simple Weighted Mean of Grades and Extra Credit

Simple Weighted Mean of Grades and Extra Credit

Randy Wald -
Erantzun kopurua: 3

Hi everyone,

I am wondering.. is it possible to have extra credit with simple weighted mean of grades? I am working with an instructor and the calculations do not appear to be correct.


We have four categories.

1. Category set up for a series of 50-point essays. (SWM)

2. Category set up for Assignments each worth 20 points. (SWM)

3. Category set up for Exams each worth 150 points. (SWM)

4. Category set up for Extra Credit from Forums each worth 10 points. (Sum of grades set to extra credit)

The over-all category is set to SWM and all SWM categories are set to aggregate only non-empty grades. All categories with SWM have 100 point totals for the category.

Should this work in Moodle?

The instructor thinks we should be able to add up all the points and devide by the total possible (which don't include the extra credit)...and come up with the same number. But I think the weighting will total different.
Randy

Randy Wald(e)ri erantzunda

Re: Simple Weighted Mean of Grades and Extra Credit

Bob Puffer -

The intructor is wrong.  Each category that has a category total of 100 points will be equal to each other category worth 100 points.  Your calculation will look something like this:

((Cat A % correct over the whole category) + (Cat B % correct over the whole category) + (Cat C % correct over the whole category)) / 100 (in order to scale the aggregate of the category totals to 100%.  Then any points from your extra credit category will be added in to a maximum of 100 (% or real) unless you've enabled unlimited grades in which case the extra credit could push the total over 100.

Its an unfortunate consequence of the core gradebook that it totals categories to 100 by default (CLAMP's LAE Grader doesn't do that).  If you wanted to achieve what your instructor describes you'd have to either have all the non-extra credit items in the same category or else input accurate point totals for your non-extra credit categories so the categories would be weighted unevenly, not all worth 100.

Bob Puffer(e)ri erantzunda

Re: Simple Weighted Mean of Grades and Extra Credit

Randy Wald -

Bob,

Thank you. I think we'll probably put everything in one category as suggested.

Randy

Randy Wald(e)ri erantzunda

Re: Simple Weighted Mean of Grades and Extra Credit

E. L. Cooper -

Personally I have school who uses category totals to weight the grades- which is to say the category total for lessons is 30, the category total for essays is 10 etc. All regular credit categories adding up to 100 and 5 on extra  credit but the extra credit grades are hidden and added in manually after a student finishes the class. One thing that does occur is that if a student does not do everything the category totals are correct but the class total gets knocked off. To account for that I had them use grade calculation for the sum of categories. I have the document I wrote to 'take' them through the process somewhere.