What calculation methods are available for outcomes?
When creating an outcome, you can specify one of four calculation methods used for student mastery: Decaying Average, n Number of Times, Most Recent Score, and Highest Score. Calculation methods are used in conjunction within the Learning Mastery Gradebook.
- For new Outcomes created in the Canvas interface, the default calculation is Decaying Average unless changed to another calculation.
- For new Outcomes created using the Outcomes API, the default calculation is set as Highest Score but can be modified with the appropriate parameters.
- If you import an outcome that you don't have permission to modify, you cannot change the calculation method.
- Common Core outcomes are always calculated as Highest Score; however, the calculation method can be modified using the Outcomes API by any user with appropriate admin permissions.
Set Decaying Average
The Decaying Average calculation factors the average of all assessment items while weighing the most recent (current) item at a higher percentage.
The term decaying average is traditionally used to describe a complex analysis: when an additional assessment is applied to an existing value, the prior decaying average is used to calculate the new decaying average. This method weights all assessments equally and calculates the average of learning over time. However, the Canvas method uses a simplified approach where Canvas calculates the average of all prior assessments and applies the value as a weighted percentage formula, instead of the alternative approach of simply using the prior decaying average.
By default, the Canvas decaying average is set at 65/35, meaning the current item is weighted at 65%, and the average of all other user scores is weighted at 35%. However, users can specify between 1% and 99% for the current percentage, and prior scores are weighted against the percentage difference. Note that the average is rounded to the next two decimals. If there is only one result, then the single score will be displayed.
For example, a student has four aligned items with scores of 4, 3, 2, and 5 (scores listed chronologically from oldest to most recent). If the current item is set to be weighted at 75% of mastery, prior scores are weighted at 25%:
- Current item score: 5
- Average of prior item scores: (4 + 3 + 2) / 3 = 3
- Calculated score: 5 (.75) + 3 (.25) = 3.75 + .75 = 4.5
Set n Number of Times
The n Number of Times calculation requires a specific number of times that mastery must be met or exceeded, and the number of aligned items that must be completed for calculation eligibility. Any scores that do not meet mastery are not part of the calculation.
Users can specify between 1 and 5 items required for mastery.
For example, a student is required to achieve mastery 2 times with a mastery score of 5. If the student has scores of 1, 3, 2, 4, 5, 3, and 6, only the scores of 5 and 6 would be part of the calculation.
- Average score of eligible items: 5 + 6 = 11
- Calculated score: 11 / 2 = 5.5