Extra credit using weighted assignment groups.

Community Team
Community Team
18 14 28.7K

Canvas has a number of ways to manage extra credit (and for an explanation, see Not authorized to view the specified document 2874). This document will elaborate on one of the options discussed briefly in the Canvas Guide, namely, using weighted assignment groups to grant extra credit.

My approach to offering extra credit in my fully-online classes is to allow students to augment their grades by demonstrating robust participation in ungraded discussion topics (the assignment is pictured at the end of this document). On the first day of classes, in the syllabus, and through course announcements, I advise students that they can earn the extra credit over the course of the semester, and that they will be able to see their contributions reflected in their grades after the last day of classes passes.

So that Canvas can factor the grade for the extra credit assignment into the final grade automatically, I use a weighted assignment group scheme in which the required assignments in the course add up to 100%. I then create an additional assignment group, worth 0%, called "Extra Credit: Participation," and I place a single assignment in that assignment group. You can make the assignment itself worth any number of points that makes sense for the requirements of the assignment and the grading rubric you plan to use. I mute the assignment so that I can grade it behind the scenes.

After the last day of classes, and before I have to submit my students' final grades, I grade the extra credit assignment, making sure to assign a grade of zero to any student who did not complete the activity. At that point, I change the weighting on the extra credit assignment group from 0% to 1.4%. The 1.4% grade contribution is my personal preference; you can use any extra credit percentage with which you're comfortable, as long as it's greater than 0%. Lastly, I unmute the extra credit assignment. Students will now see how their extra credit contributions have impact their final grade.

Note:

  • It's best to use this approach only if you're willing to wait to grade until after all of the other assignments have closed before granting the extra credit. If you don't, and if the extra credit assignment group contributes anything other than 0% to the final grade in the meantime, students will see a somewhat confusing reflection of their cumulative course grade. james@richland.edu explains this better than I ever could:

I think the most useful solution I've found...is to make the extra credit worth 0% until the end of the semester. This is especially important when you have a category like "final exam" that's worth 30% of your grade. Until your assignment groups that actually have grades in them exceed 100%, Canvas will scale the grades. So, if you have homework 20%, exams 50%, final exam 30%, and extra credit 10%, until the score is entered for the final exam, you have 20%+50%+10% or 80% of the grade. Since that's less than 100%, what you're calling "extra credit" isn't considered extra credit by Canvas (you can't have extra credit if you don't have more than 100%) and gives a wrong (in your thinking) grade.

If someone has 90% on homework, 60% on exams, and 100% of extra credit, then they have 90*20%+60*50%+100*10%=18+30+10=58% out of a possible 80% which gives them 72.5% for the class. What you want them to see is 90*20%+60*50%=18+30=48% out of 70%, which is 68.6% for the class, or maybe you want 68.6%+10% extra credit = 78.6%. I'm not sure, but you probably don't want the 72.5%

Now, when the final exam grade is added (let's say they got a 42% on it), you have 90*20%+60*50%+42*30%+100*10% = 18+30+12.6+10 = 70.6% for the class. Since there is now 110% possible, which is more than 100%, Canvas doesn't scale the result to make it worth 100% and so the extra credit works the way people expect.

  • If you want to allow your students to choose from multiple extra credit opportunities, you can put multiple options within the Extra Credit assignment group and adding grading rules to the group. If you do this, you will need to assign grades to every student, including zero grades for any students who did not complete the extra credit.
  • Or, you can use separate Extra Credit assignment groups for each opportunity.
  • For those of you who are interested in seeing the actual assignment I use to measure course-long participation, I'm providing a screenshot below. james@richland.edu's excellent resource--How to Count Student Discussion Posts--is invaluable in this regard, in that before he devised this solution, I had to do manual searches by student name and tabulations on scratch paper. James's solution is considerably easier to implement than it looks on first blush.Smiley Happy
  • If you want to create an extra credit quiz, be sure to check out kona@richland.edu's solution: Creating an Extra Credit Quiz

Sample Extra Credit Assignment for Course Participation

Sample Extra Credit Assignment

(Last, it's worthwhile to mention here that garth@academicplatforms.com has devised a method of overriding a grade with the end result of lowering it; his goal is the opposite of awarding extra credit, but he uses the same methodology as what I've described above: Override / Adjust the Final Grade)

14 Comments
Navigator

Golly-gee stefaniesanders​, thanks for the kudos. I think you and kona@richland.edu​ were the ones who suggested waiting until the end of the semester to add the extra credit. I was just trying to show how the math works.

If you're using assignment groups with percentages, then your final score is just a weighted average, using the assignment group percentages as the weight. I may use "category" instead of "assignment group" to improve understanding.

Mathematically, a weighted average is found by multiplying each value by its weight and then adding those up. You then divide that total by the sum of the weights.

Grade point average is a classic case of a weighted average (the credit hours serve as the weights). So, on a 4.0 scale with an A in a 2 hour class and a C in a 5 hour class, you would have (2*A + 5*C)/(2+5) == (2*4 + 5*2)/(2+5) = 18/7 = 2.57 for the GPA.

In the case of the Canvas Gradebook, the weights are the percentages assigned to each category (assignment group).

A student's grade is found by multiplying the student's percent in each category by the category's weight (assignment group percentage) and then adding those together.

As long as the sum of the category percentages is at least 100%, that's the score the student gets.

The astute reader will see that I didn't mention dividing by the sum of the weights. That's because, in a gradebook, the sum of the percentages should be 100% (1) and dividing by 1 doesn't change the value. If someone has more than 100% in their assignment group percentages, Canvas assumes they want anything above 100% to be extra credit and so dividing by the total sum of the percentages would scale it back to 100% and remove any extra credit.

However, if the sum of category percentages is less than 100%, then you need to divide by the available percent to make it a weighted average. So, if you are missing a final exam grade and only have 70% of the grade available so far, you divide the weighted average by 70% (0.70) to scale it to be worth 100%.

Missing grades are what seems to cause problems for people.  As long as all of the grades are in, everything works fine. But if there are items missing, then people get confused.

That missing item could be because an assignment group has no assignments that are worth points. I have a discussion reminders group with no graded assignments (that will be disappearing next term) that isn't worth any points so I avoid any ambiguity by also assigning that group 0% of the grade.

That missing item might be because a student hasn't submitted it yet or the teacher hasn't graded it. Unless the teacher goes in and tells the Gradebook to "Treat ungraded as 0", then any item missing a grade is not included in the grade calculations. If that's the only item so far in an assignment group, then the assignment group won't get counted in the grade (and you're back to the less than 100% issue)

Missing grades can cause there to be less than 100% available on a student-by-student basis, which means that some students may be getting extra credit as extra credit and other students are having it rolled into their regular grade.

When the percentages add to less than 100%, the scores are scaled to be worth 100%, and that's what students see unless a student unchecks the box to calculate their grade based only on graded assignments. Then they'll get 0's for all ungraded assignments, their grades will plummet, they'll freak out, but at least they'll know what they would get if they didn't do any more work for the rest of the course.

141597_pastedImage_2.png

There is a feature request   that is open until Feb 3, 2016, that talks about how this issue is confusing to students and it should be unchecked by default. I disagree with the feature request, thinking that if you start students off with 0% and only show them what they have earned so far, it's going to cause more confusion than saying here's the level you're performing at based on what you've submitted and has been graded. But if someone favors it, they can go vote for it.

I think education on the part of the teacher can go a long way to alleviating some of the problems with grades. Unfortunately, that means that the teachers need to understand it themselves first, so I applaud you writing this document to help.

Community Team
Community Team

I'm curious to know what people think of enhancing this process to incorporate the new "do not count" setting now available in assignments. I haven't tried this yet--but if I were to enable the "Do not count this assignment towards the final grade" setting until the end of the semester, I wouldn't have to have the assignment muted. Instead, I could calculate the grade monthly, using the rubric; students could see how they're doing, and they would know that they will see the grade impact at the end of the semester when I change the weighting for the assignment group.

Pros? Cons?

Community Member

I read this info a while ago, so I hope my comment isn't redundant.  I use a weighted grading system.  When I want to add an extra credit "assignment" to one of the categories, I make it worth .01 points.  I'm a high school math teacher, and they have LOTS of homework points, so if one student's possible points is a few hundredths more than another student's, the effect on the grade is minimal.  Also, when I post grades to Power School, the points possible are read as zero, which is exactly what I want it to be. 

Explorer III

Hi Everyone,

 

After reading what works for others when adding an Extra Credit Assignment while using Weighted Groups, the following 2 options seem to be popular:

  1. Create a zero point Extra Credit Assignment and place it into one of your Weighted Groups that contains points. However, according to james@richland.edu, that may result in a different percentage for the Extra Credit than intended. 

 

  1. Create a zero point Extra Credit Assignment and place it into a separate Group worth 0% that you Weight at the end of the course (such as stefaniesanders 1.4%). Unfortunately, that option does not allow students to see their current grade throughout a course.


Since Canvas allows a grade book that totals over 100% and only totals assignments in which we insert points, could something like this work?:

  1. Create Assignment Groups that total 100%
  2. Create a separate Assignment Group named Extra Credit that is Weighted with a percentage (such as 1%), so the Assignment Groups Total 101%Weighted Assignment Groups that Total over 100%

  3. Add an Assignment that contains the highest point value possible for Extra Credit and place it in the Extra Credit Group that is worth 1%.
    Extra Credit w_Points
Navigator

dejonghed07@macomb.edu ,

Probably not unless you're one of those people who puts in 0's for everything ahead of time. I'm going to exaggerate the extra credit to 10% just to show the differences more.

Assignment groups without grades in them do not count in the total, so as long as you don't put down a 0 for a student in an extra credit group, then it won't factor into the grade and the grade will be based off the other groups.

So, if a student hasn't taken their exam (say their final) then that isn't included in the grading and there is only 50% of the points possible (in my example below).

232294_pastedImage_2.png

But if you put in a 0 for extra credit, then extra credit is included, but since there is still only 50% of the grade in, it's not considered extra credit.

232300_pastedImage_5.png

If you have missing grades, like no final AND you include extra credit when they get some, then you really screw the student up because they got everything right PLUS 4/5 on the extra credit and their grade dropped to 96%. This happens because there is no sense of extra credit UNTIL the weights are more than 100%. Right now, we've got 40% homework + 10% extra credit = 50%, so there really is no extra credit yet.

232298_pastedImage_3.png

Once you throw in that exam score, there is now 110% possible, so anything above 100% is extra credit.

232299_pastedImage_4.png

In short, until the weights of the assignment groups add up to 100% (or more), there is no such thing as extra credit. Canvas does not read the name of the category and try to interpret it as extra credit.

Explorer III

Thank you james@richland.edu - Your visual description is helpful! There doesn't seem to be an ideal option for including extra credit when assignments are in weighted groups. As you and Stefanie stated, it's best to wait until the end of the course. However, students who submit extra credit assignments won't know their grade in a course at all times. 

Community Coach
Community Coach

dejonghed07@macomb.edu, technically the students could figure up how much the extra credit is worth (percentage wise) and just add it to their course grade.

Ex: If the extra credit is worth 4% (added to the normal 100% for the course) and there are two assignments a 10 point and a 20 point assignment. This is what the student could do if they got the following grades 10/10 and 5/20.

Add the total points they got (10 + 5 = 25) and the total points possible(10 + 20 = 30) and then divide the total points they got by the total points possible --> 15/30 = 0.5. Then multiple this by the percentage the extra credit is worth (in this case 4%) --> 0.5 X 4 = 2. This is the percent their grade will be raised by the extra credit. So if the student is getting a 84% without the extra credit they are getting an 86% (84 + 2) with the extra credit.

Community Coach
Community Coach

dejonghed07@macomb.edu, while it doesn't deal directly with extra credit, the following could be tweaked to help students also understand how extra credit factors into their grade - https://community.canvaslms.com/people/kona@richland.edu/blog/2017/05/01/student-activity-understand...

Community Coach
Community Coach

Hi james@richland.edu. I have been working with a faculty member on this issue and have a question I was hoping to get your insight into.  You mention missing grades being a problem.  Is it important for ALL grades to be in for Canvas to calculate over 100% weighting correctly or is it only important for one graded assignment in each weighted category to be entered before you can change the extra credit group from 0% to 5% (for example) and have the calculations work the way intended? Thanks!

Navigator

ericwerth,

Only categories where the student has a graded assignment is counted. As soon as the student has at least one grade for each of the categories, you can exceed 100% to get the rest counted as extra credit. It is not necessary to have all of the grade for each student entered. It will, of course, only calculate the grades based on what has been submitted for that student.

Quasi-related (but not really what your question is about), that last sentence may cause confusion for some who want the grades to represent what they have earned out of the total, not their average so far. For example, if there is an assignment group called "Exams" that has 3 assignments worth 100, 100, and 200 points respectively. As the semester proceeds, the grade will be based on what has been entered, so a student that scores an 80 and a 90 on the first two would have (80+90)/(100+100)=170/200=85%. For the faculty that want them to see 170/400 = 42.5%, that's not the way Canvas gradebooks work unless you go through and put in 0's for everything at the beginning. What does that have to do with extra credit?

Probably the thing more important to note is the word I repeated in each sentence in the first paragraph -- student. This grading is done on a student-by-student basis, so if assignments are missing for some students but not others, then some students may have met the one-grade-in-each-group while others have not. Those who have not would experience the extra-credit-isn't-really-extra grading issue until they get at least assignment groups adding up to 100%. Of course, if there was a 5% assignment group and a 5% extra-credit assignment group and the student didn't have a grade in the first but they did in the second, then the extra-credit wouldn't be extra-credit.


I feel like I wrote a whole bunch that didn't say anything if you go with the big picture -- make sure every student has a grade in every assignment group before adding the extra credit in there.

Community Coach
Community Coach

Thanks james@richland.edu!  We do run into the "As the semester proceeds, the grade will be based on what has been entered, so a student that scores an 80 and a 90 on the first two would have (80+90)/(100+100)=170/200=85%. For the faculty that want them to see 170/400 = 42.5%, that's not the way Canvas gradebooks work unless you go through and put in 0's for everything at the beginning. What does that have to do with extra credit?" situation, particularly around midterms when some faculty don't want to enter a grade that doesn't represent the final weighting of the course.  Then again, the student hasn't earned a lower grade either so it doesn't seem right to enter a 45% if they have scored 80% and 90% on the two exams.  Most faulty don't want to enter an "F" either, but there is the issue of what % of a groups weighting has been earned at any particular date when at midterms, for example, 1 out of 3 exams may be worth 30% of the total weighting (meaning that exam is currently worth 30% of their grade) but at the end of the class each exam will only be worth 10%.  One faculty was considering entering zeros for all assignments at the beginning of the class, but since we are getting an early alert system that is supposed to help raise red flags when students are at risk of failing a course, there would be a long period of time where students who are actually doing fine would be indicated as having a failing grade if this were done.

One follow up question if you don't mind.  You mention toward the end of your message that if there is a 5% assignment group and 5% extra credit assignment group and the student didn't have a grade in the assignment category but did in the extra credit group, then it wouldn't be extra credit.  This would suggest that if a student didn't do extra credit so had nothing entered into the extra credit category and didn't have grades in the assignment group as well, that the actual weightings of the other categories would effectively be higher since the student's total grade still would be 100% somehow, and that the student who did do extra credit would have that 5% in a single category composing their grade rather than distributed otherwise, correct?  Then when everyone has a grade in all the assignment groups at some point, the extra credit would represent an addition to the other 100%.  Is this right?  I'm not even sure that I explained this clearly!  

Thanks again.

Navigator

ericwerth,

One follow up question if you don't mind.  You mention toward the end of your message that if there is a 5% assignment group and 5% extra credit assignment group and the student didn't have a grade in the assignment category but did in the extra credit group, then it wouldn't be extra credit.  This would suggest that if a student didn't do extra credit so had nothing entered into the extra credit category and didn't have grades in the assignment group as well, that the actual weightings of the other categories would effectively be higher since the student's total grade still would be 100% somehow, and that the student who did do extra credit would have that 5% in a single category composing their grade rather than distributed otherwise, correct?  Then when everyone has a grade in all the assignment groups at some point, the extra credit would represent an addition to the other 100%.  Is this right?  I'm not even sure that I explained this clearly! 

I've had too long of a week and am too tired to follow that right now, so I'll just write and hopefully answer the question before I fall asleep at the keyboard.

First, there is no concept of an "extra credit" assignment group in Canvas. You can call it "extra credit", but that's a human thing, not a Canvas thing.

In a weighted gradebook, Canvas finds the weighted average of the proportion of the points (a percent expressed as a decimal) achieved in each assignment category.

The weighting occurs by the percents assigned to the assignment group weights, but it's capped at 100%

If a course has 3 assignment groups and the student has grades in all three groups, then the weighted grade looks like this:

weight1 * proportion1 + weight2 * proportion2 + weight3 * proportion3

----------------------------------------------------------------------------------------------

MIN ( 100, weight1 + weight2 + weight3 )

The MIN(100 ...) line says to take the smaller of 100 or the sum of the weights. So, if there are only 80% of the grades accounted for, then the smaller of 100 and 80 is 80 and the denominator will be 80. If there is 105% possible, then the smaller of 100 and 105 is 100, so it will divide by 100. That's where the extra credit comes in.

Canvas doesn't know that you've designated the group called "Extra Credit" as extra credit. It just knows MIN(100, sum of weights).

If you had two groups that were worth 45 and 60 percent of the grade, then you have 5% extra credit once grades are in both. But there's not a separate assignment group for extra credit. You can also have extra credit on individual assignments, so even though the weights may add to 100%, your proportions are greater than 1 and you end up with extra credit. Then you get the students coming in every semester for their favorite teacher and saying "I got 100% but my grade went down" and you get to explain that "When you have 120% in the class (no wonder it's their favorite teacher), 100% is lower than your current average of 120% and so it lowered your grade."

Let's say a teacher has:

80% Exams

15% Homework

5% Cookie Challenge

5% Extra credit

The Cookie Challenge doesn't occur until the end of the semester.

Let's say a student has completed work in Exams and Homework and scored 70% and 90% respectively. That student has

(80*0.70 + 15*0.90) / (80 + 15) = 0.73157894736 = 73.16% for the course.

So right now, the student has exams, homework, and some extra credit. Canvas will consider the 80+15+5 to get 100% and so the extra credit isn't extra, it's part of the grade.

A student who had 70% on exams, 90% on homework and 100% on extra credit would get

(80*0.70 + 15*0.90 + 5*1.00) / ( 80 + 15 + 5 ) = 0.745 or 74.5% for the course.

Another student who had 70% on exams, 90% on homework and 0% on extra credit would get

(80*0.70 + 15*0.90 + 5*0.00) / ( 80 + 15 + 5 ) = 0.695 or 69.5% for the course.

 

So the student who averaged 70% and 90% on things and had a 73.16% before doing the "extra credit" is now getting a 69.5% because extra credit isn't extra credit until there's more than 100% available.

Let's go back and say there's no extra credit, but they have completed the Cookie Challenge and both received 50% of the possible points there.

(80*0.70 + 15*0.90 + 5*0.50) / (80 + 15 + 5) = 0.72 = 72% for the course.

When you throw in the extra credit, the weights now exceed 100%, so they're capped at 100%.

(80*0.70 + 15*0.90 + 5*0.50 + 5*1.00) / 100 = 0.77 or 77% for the course for the person with 100% of the extra credit, and 

(80*0.70 + 15*0.90 + 5*0.50 + 5*0.00) / 100 = 0.72 or 72% for the course for the person with no extra credit

Once you have more than 100% in assignment groups that contain graded assignments, then extra credit can't hurt you. But until then, putting something into a group called extra credit could hurt you if you didn't get the extra credit.

All that is because Canvas doesn't know it's extra credit, it's just another assignment group.

Like I said, I'm tired and so hopefully the math is all right and that made sense.

I think that when talking about assignment groups, it boils down to "extra credit" is a human label that Canvas does not understand or interpret any differently than "Homework", "Exams", or "Cookie Challenge".

Community Coach
Community Coach

Thanks for the example!  That helps answer my question.  I hope you get some rest this weekend!

Navigator

Somehow I missed this question about the don't count towards the final for over a year. Apologies.

It could work when there is a single or perhaps just a few extra credit assignments. It definitely is an approach to consider when you're not using a weighted gradebook and so you can't set an "extra credit" group to be worth 0% of the grade. The downside is going back in at the end and remembering to uncheck the box and it's harder to do that muting/unmuting, which I'm not a big fan of anyway, since you would have to edit the assignment for every assignment that you did this to, while muting and unmuting can be done from the gradebook.

If I wasn't using a weighted gradebook, I think I would choose this over muting, because I want students to be able to see what they've accomplished.