Canvas Data for Grading
In this article, we will show you how Canvas stores its grading data. We will use the following example:
BUS101 is a course in Canvas (Canvas Course Id:1788). There are 3 students enrolled into this course. Their Canvas Student Id is listed next to their name for reference purpose.
BUS101 is made up for 3 assignment groups.
Assignment Group |
Weightage |
| Assignment 1 | 25% |
| Assignment 2 | 25% |
| Assignment 3 | 50% |
If we take Student2:4048 as an example, the total score of 89.25% is calculated based on the following formula:
Assignment 1 Mark * Assignment 1 Weightage + Assignment 2 Mark * Assignment 2 Weightage + Assignment 3 Mark * Assignment 3 Weightage
85 * 25% + 90% * 25% + 91% * 50% = 89.25%
Behind the scene, this is the data we can retrieve via Canvas API.
Info
The response document does not have the full list of fields returned from Canvas API. We have ommitted the irrelevant fields in this article.
/api/v1/courses/1788/assignment_groups [ { "id": 5255, "name": "Assignment 1", "group_weight": 25.0, }, { "id": 5256, "name": "Assignment 2", "group_weight": 25.0, }, { "id": 5257, "name": "Assignment 3", "group_weight": 50.0, } ]
If we query all the assignment groups for this course (1788), you can see the weightage at group_weight.
The actual mark of each individual student is listed per assignment group per student. To retrieve it, we use another API. For example, if I want to get all the assignments for Assignment 2 (Assignment Group Id: 5256), we can do this:
/api/v1/courses/1788/assignment_groups/5256/assignments [ { "id": 6819, "description": "Assignment 2 description", "points_possible": 100.0, "assignment_group_id": 5256, "course_id": 1788, "name": "Assignment 2", } ]
In this assignment, there is only 1 assignment related to 5256 assignment groups, we can then query all the submissions using the following API:
/api/v1/courses/1788/assignments/6819/submissions [ ... { "assignment_id": 6819, "id": 200474, "grading_period_id": null, "user_id": 4048, "body": null, "url": null, "grade": "90", "score": 90.0, }, ... ]
By looking at the example above, you can see that Student 2:4048 has scored 90% in their Assignment 2 and from the Assignment Group, we know that it carries 25% of weightage.