[ARCHIVED] grade average is incorrect

[jaye_ramseysutt]

My husband and I both use Canvas at our institution--Houston Community College.  He is experiencing a problem.

We spot check averages to be careful.  Tonight, we discovered that his end of the semester grades are averaging approximately two points higher than they should. 

What could be the problem?  How do we fix this situation?  We appreciate your input and possible solutions.

Best regards

Jaye Ramsey Sutter, JD

[James · Accepted solution]

jaye.ramseysutter,

Is your husband using a weighted gradebook that has some assignment groups without any grades yet? If so, Canvas scales the existing weights to make 100%.

For example, if you only have grades in assignment groups adding up to 95% of the grade, then Canvas will multiply the scores by 100/95 = 1.052632 (see below for more information).

One thing to watch out for, which often bites people, is extra credit. With a weighted gradebook, there is no extra credit in groups until the weights of the assignments passes 100%. If you have categories adding up to 90% with a 10% final project (not yet graded) and a 5% extra credit group, then all you really have is 95%, so it does the scaling as mentioned above.

What it really does is take the weighted average, which includes dividing by the sum of the weights.If you have 30% homework, 60% tests, 10% final project, and 5% extra credit and there is no final project yet, then the following would happen (I'm making up the student scores)

Group	Student Score	Weight	Product
Homework	98%	30%	29.4
Exams	45%	60%	27.0
Final Project		10%
Extra credit	75%	5%	3.75
Total (accounted	63.32% (60.15/0.95)	95%	60.15

The 60.15 that you think the student should have is divided by 0.95 (multiplied by 100/95) to make it out of 100 percent.

That Final Project assignment group is completely ignored since it has no grades in it.

What most people is happening is this:

Group	Student Score	Weight	Product
Homework	98%	30%	29.4
Exams	45%	60%	27.0
Final Project		10%	0.0
Extra credit	75%	5%	3.75
Total (accounted	60.15%	105%	60.15

But that's not how Canvas does it.

Now, once that final project is in, we get this

Group	Student Score	Weight	Product
Homework	98%	30%	29.4
Exams	45%	60%	27.0
Final Project	82%	10%	8.2
Extra credit	75%	5%	3.75
Total (accounted	68.35%	105%	68.35

This time, there is no scaling applied because there is at least 100% available and the 68.35 that the student gets is what the student gets.

There are some lengthy discussions here in the Community on here involving weighted gradebooks and extra credit. Someone else probably has the links to those bookmarked. I know that  @kona ‌ and stefaniesanders‌ had been frequent contributors to those discussions. One of them is here: https://community.canvaslms.com/docs/DOC-5612-extra-credit-using-weighted-assignment-groups 

There is also an explanation in the blue notes at the top of the Canvas Instructor's Guide page on How do I weight the final course grade based on assignment groups? . The Canvas Guides have lots of answers to other questions, but sometimes they aren't clear enough.

[James · Accepted solution]

jaye.ramseysutter,

Is your husband using a weighted gradebook that has some assignment groups without any grades yet? If so, Canvas scales the existing weights to make 100%.

For example, if you only have grades in assignment groups adding up to 95% of the grade, then Canvas will multiply the scores by 100/95 = 1.052632 (see below for more information).

One thing to watch out for, which often bites people, is extra credit. With a weighted gradebook, there is no extra credit in groups until the weights of the assignments passes 100%. If you have categories adding up to 90% with a 10% final project (not yet graded) and a 5% extra credit group, then all you really have is 95%, so it does the scaling as mentioned above.

What it really does is take the weighted average, which includes dividing by the sum of the weights.If you have 30% homework, 60% tests, 10% final project, and 5% extra credit and there is no final project yet, then the following would happen (I'm making up the student scores)

Group	Student Score	Weight	Product
Homework	98%	30%	29.4
Exams	45%	60%	27.0
Final Project		10%
Extra credit	75%	5%	3.75
Total (accounted	63.32% (60.15/0.95)	95%	60.15

The 60.15 that you think the student should have is divided by 0.95 (multiplied by 100/95) to make it out of 100 percent.

That Final Project assignment group is completely ignored since it has no grades in it.

What most people is happening is this:

Group	Student Score	Weight	Product
Homework	98%	30%	29.4
Exams	45%	60%	27.0
Final Project		10%	0.0
Extra credit	75%	5%	3.75
Total (accounted	60.15%	105%	60.15

But that's not how Canvas does it.

Now, once that final project is in, we get this

Group	Student Score	Weight	Product
Homework	98%	30%	29.4
Exams	45%	60%	27.0
Final Project	82%	10%	8.2
Extra credit	75%	5%	3.75
Total (accounted	68.35%	105%	68.35

This time, there is no scaling applied because there is at least 100% available and the 68.35 that the student gets is what the student gets.

There are some lengthy discussions here in the Community on here involving weighted gradebooks and extra credit. Someone else probably has the links to those bookmarked. I know that  @kona ‌ and stefaniesanders‌ had been frequent contributors to those discussions. One of them is here: https://community.canvaslms.com/docs/DOC-5612-extra-credit-using-weighted-assignment-groups 

There is also an explanation in the blue notes at the top of the Canvas Instructor's Guide page on How do I weight the final course grade based on assignment groups? . The Canvas Guides have lots of answers to other questions, but sometimes they aren't clear enough.

[jaye_ramseysutt]

We don't do complicated math

No homework.  Exams and a paper only.

We have four exams and one required research paper.  We drop the lowest grade of the exams and the paper is mandatory.  So everything weighs 25 percent.

Grades entered at the time of the exam completion.  We graded our research papers.

Canvas isn't averaging four grades properly.  They are off 2-5 points. 

Why would that be?

[kona]

Could you provide the Assignment groups and weights, assignments in each group, and then one or two students graded for all the assignments? We would need this information to help you troubleshoot this. 

[James]

jaye.ramseysutter ,

Echoing what  @kona ‌ said, can you provide the settings and the full grades (without identifying information of course) for some students whose scores you think are being calculated incorrectly?

In the almost 5 years I've been using Canvas, I've never seen it calculate a grade wrong. I've seen other people here in the Community suggest contacting Canvas Support because it's a bug, but any one I have looked at has always been calculated correctly (granted, I'm a math teacher and can read some computer code to see what's going on so I might have an advantage over some). I have seen lots of cases where what people think should happen isn't what's happening. One of those areas is when grades are dropped, especially if the point values are not the same. Without explicitly stating that, you're implying that they are all the same when you say 25%, so that's why seeing how things are setup would help.

One way to accomplish what you're describing, is to have a single assignment group, drop 1 score, and never drop the research paper.

Then, let's say I entered these grades

Exam 3 with the gray background is the one that is dropped, even though the research paper is a lower score. That's where the "Never drop" comes in. The counted scores are 90+85+97+25=297 out of 400 points, which is 74.25%.

If the research paper is missing, then you get this:

It still drops the 75 for exam 3, but there are only 272 points out of 300, which is 90.66666... and gets rounded to 90.67%

If you have the research paper, but not the exams entered, then you might get something like this:

It still drops the exam 3 score and now you have 200/300 for 66.67%.

All of the calculations are spot on and most people have no trouble following the calculations.

Where things get tricky is if you have different point values.

Notice that they got 40/50 = 80% on Exam 1 and 75/100 = 75% on Exam 3, but Canvas drops Exam 1, not Exam 3.

Canvas does not drop the lowest percentage, it drops the grade that hurts the most, so it is correct to drop Exam 1.

• Dropping Exam 1: Exam 2 + Exam 3 + Exam 4 + Research
  • Student points: 85 + 75 + 72 + 25 = 257
  • Possible points: 100 + 100 + 75 + 100 = 375
  • Final average = 257/375 = 68.53%
• Dropping Exam 3: Exam 1 + Exam 2 + Exam 4 + Research
  • Student points: 40 + 85 + 72 + 25 = 222
  • Possible points: 50 + 100 + 75 + 100 = 325
  • Final average = 222/325 = 68.31%

Dropping Exam 1 results in a higher final percentage for the student (68.53% vs 68.31%), so that is the one that Canvas drops. The fact that the student did better percentage-wise on Exam 1 (80%) than Exam 3 (75%) is irrelevant and not figured into the calculations. The decision about which one to drop is based on the overall grade. You may lose the battle (drop an exam with a higher score) to win the war (end up with the higher grade).

While the above approach -- a single assignment group, drop 1 grade, never drop the research paper -- is the easiest route, there are other ways you could go. You could set up two assignment groups, one for exams and one for the research paper. Then drop one assignment from the exam group and don't drop any from the research paper group. Sorry I can't include a screenshot right now, my beta instance of Canvas has gone into maintenance mode and I want to get this message out sooner rather than later.  Other people could use a weighted gradebook and if they did that, they would need to make the Exams worth 75% of the grade and the research paper worth 25% of the grade. They would still need to apply the "drop 1 lowest grade" rule.

The most common concerns about the gradebook being wrong deal with extra credit, dropping assignments, missing assignments, and weighted assignment groups. If the above doesn't explain the discrepancy, then we really will need to see what you think is a wrong calculation along with any rules (dropping grades) that you have to help.

[Chris_Hofer]

Hello jaye.ramseysutter‌...

I noticed that there hasn't been any new activity in this discussion topic for quite a while, and so I thought that I would check in with you.  Have you had an opportunity to review the additional responses that you've received from  @kona ‌ and  @James ‌?  It looks like they need a bit more information from you.  After you've had a chance to review the above responses, if you feel that one of them has answered your question, please feel free to mark it as "Correct".  However, if you still have some questions related to your initial posting, please post a message below so that members of the Canvas Community can continue to assist you with your question.  For now, since there hasn't been any new activity in this thread for quite a while, I'm going to mark your question as "Assumed Answered", but that won't prevent you or others from posting additional replies below.  I hope that's okay with you, Jaye.  Looking forward to hearing from you soon!

[jaye_ramseysutt]

I thought I would look at this tonight.

Frankly I don't understand the reply.  I fail to see how it even applies.  How can I get the gradebook to average grades without being off by one point?

I have five grades.  Each grade is 20%.  As I look at the averages tonight, the grades are off by 1 point.

How in the world does that happen?  I don't weigh assignments.  I don't drop grades.  Five grades averaged by five.  One point off.  Each assignment is 100 possible points.  Every students' grade is off by one point.  Some students won't get the next letter grade because of this.  Fortunately I am dealing with one class of 32 people so it isn't horrible and most students aren't affected.

If I use a calculator, I get an accurate average.  If I go by Canvas students' grades are off by one point.

[j_fielder]

I am currently having this same issue. I just started the term at my institution and have been using Canvas for about 6 years now with no issues in terms of grading.

For this particular course I have no weighting applied to my assignment groups. I currently have 2 groups under assignments - 1. Assignments, and 2. Weekly reviews. At this point I have published and graded 2 sets of submissions for "Assignments" which are displayed as complete or incomplete, and 1 group of submissions for "Weekly Reviews." The problem is that students who have completed both assignments are receiving an 80% average for the Assignment group when they should have 100%. I am not giving anyone partial credit for these as they are either complete or incomplete, and again, I am not applying weighting to any of my assignment groups. 

Is there some reason that this is happening? Or is there some way to fix it. I have a group of very nervous students who believe they are doing worse in the class than they actually are because Canvas doesn't seem to be averaging grades correctly (or I've done something that is very incorrect on the back end).

Image of gradebook is attached. 

Thanks,

Jon

[James · Accepted solution]

 @j_fielder ,

It sounds like you're focusing on the wrong thing. It's not the 80% that's troublesome, it's the 75% for the students in rows 2-4 that is the issue.

My first guess is that you think the checkmark means they got the full 10 points and that's not necessarily the case. A checkmark means they got something above 0 points.

For instance, here is a portion of a gradebook where I had a 10 point assignment.

If I go into the the assignment and change it from "points" to "complete/incomplete", then I get this when I reload the gradebook.

However, the overall grade for the first student is calculated based on them getting a 5, not on a 10.

There are a couple of ways I can think of this happening.

The first is that you had an assignment that you changed from points or percentage to complete/incomplete. For those three students in the middle, you entered 5 or 50%. Later you decided just to make it complete/incomplete and not worry about the score they got on it so you changed it. Seeing the checkmark, you thought that Canvas automatically changed the score -- but it didn't.

I'm not using the new gradebook to know if this is still what it looks like or not, but if there is a late penalty in place for those items, then the student won't have the full 10 points, despite having the checkmark.

I'm sure there are other scenarios, but my guess is that if you change the "complete/incomplete" to points that you'll find some of those checkmarks aren't the full 10 points.

[kdj05d]

Thanks for this suggestion! This is exactly what happened, I had several complete/incomplete checks, but one I changed half way through grading and it apparently translated my grades of 86% to 860 - why it would multiply by 100 instead of giving 50 points max is strange. I've accidentally given over 100% of the points before and it gives me a warning so I was able to correctly immediately. But with complete/incomplete checks it is different and why it hides the points it gives or gives less or more than 100% for a complete is beyond me. Anyway, doesn't exactly instill confidence, so I will never give check marks complete/incomplet ever again.

[James]

@kdj05d 

Whether to use complete/incomplete is certainly up to you, but it works well when implemented before grading occurs. Most things can fall apart when you change them in the middle of grading. Canvas works best when people decide what should be done before students engage with the assignment. I fought that for years since I'm more of a dynamic person rather than a planner, but a little bit of planning goes a long way with Canvas.

Complete/incomplete generally should be used when you want full or no points. Some people may change their mind partially through grading and Canvas allows for that in a sane way. Changing from points (or percentage) to complete/incomplete could cause a loss of data and that's typically a bad thing. Let's say a student got 5/10 points and the instructor had a moment and asked "I wonder what complete/incomplete does?" and changed it. Then they decided they didn't like it so they changed back. If Canvas changed all the scores to be full points, that instructor would have just messed up their gradebook. What Canvas does instead, is show a checkmark for any score that is positive, but retains the number in the calculations.

As for the percentage 86% becoming 860, that's not multiplying by 100. 86% times 100 would be 86 and 86 times 100 is 8600. There's no way to get 860 out of 86%. Perhaps you accidentally hit an extra 0 at the end of 86? I'm not sure why it didn't warn you. According to the How do I enter and edit grades in the Gradebook? lesson in the Canvas Instructor Guide, Canvas will generate a warning if the amount entered is 50% more than the possible points, an extra digit is entered, or an assignment is given negative points. If it does not happen for a specific type of assignment, it is usually documented.