Help with grade book Calculation Formula

Help with grade book Calculation Formula

by Greg L -
Number of replies: 7

Hi, 

I need help with my formula for my gradebook category.

Here is my problem. I have a faculty member who has 6 quizzes. 5 quizzes are worth 110 pts and 1 quiz (Q4) worth 100 pts. He is dropping the lowest quiz grade. So using the Mean of Grades aggregation his category total for Quizzes is not correct. If the lowest quiz to be dropped was the the quiz worth 100 pts then the course total is correct. BUT if the lowest is any other quiz (110pts) then the course total is not correct. BTW changing the 100pt quiz to 110pts solves it but this quiz has already been distributed. The extra 10pts was extra credit. 

Ex. Q1 = 102, Q2 = 75, Q3 = 70, Q4 = 60, Q5 = 100, Q6 = 0. Moodle total is 82.6 but correct total should be 81.4. 

So I have following formula =average(Q1, Q2, Q3, Q4, Q5, Q6) which averages the quizzes grades but I need the rest of the formula that drops the lowest number. Also, I understand we can drop the lowest grade in the category settings but when a formula is entered in the calculations it trumps that setting. Without the formula in the calculations it correctly drops the lowest. 

Help? Suggestions?

Thanks, 

Greg

In reply to Greg L

Re: Help with grade book Calculation Formula

by Bob Puffer -

Have you tried the Simple weighted mean of grade agg method. The drop lowest drops based on the contribution the item makes to the total so it should work correctly.

In reply to Bob Puffer

Re: Help with grade book Calculation Formula

by Greg L -

Thanks for your quick replies!

@Marty - I added the -min(Q1, .... to the formula and nothing happened. I would still just average all 6 grades instead of 5 (minus lowest).

@ Bob - That would and did work if the fourth quiz was worth 110pts just like all the other quizzes. But it is only worth 100pts.

We just need Moodle to average what has been entered and drop the lowest.

Any more ideas?

Thanks again.

In reply to Greg L

Re: Help with grade book Calculation Formula

by Bob Puffer -

If SWM didn't work then you should do something like this AVERAGE((g1+g2+g3+g4+g5+g6)-MIN(g1,g2,g3,g4,g5,g6))

In reply to Bob Puffer

Re: Help with grade book Calculation Formula

by Marty Soupcoff -

Bob - That will get you the sum of the scores minus the lowest but then the average function will have a single number to average. Thinking about it, the average function won't work here because we need to sum all the components and drop the lowest first. That leaves us with a large number instead of individual components.

So new calculation: =(sum(g1+...)-min(g1+...))/5

Happy Moodle Logooodling!

In reply to Marty Soupcoff

Re: Help with grade book Calculation Formula

by Greg L -

Marty,

That worked! Here is the actual formula used. =(sum(Q1, Q2, Q3, Q4, Q5, Q6)-min(Q1, Q2, Q3, Q4, Q5, Q6)) /5

The aggregation for the course is Mean of Grades and the aggregation for the category is Mean of Grades.

Much appreciated especially right before grades need to be submitted.

Thanks again. Happy Holidays!

- Greg

In reply to Marty Soupcoff

Re: Help with grade book Calculation Formula

by Bob Puffer -

You're absolutely right and I wasn't thinking about it very carefully when I wrote the formula