Calculations
Calculation types
This section lists all the different calculation types that are available in the Edit|Calculation command. These are:
- Average
- Average highest tasks
- Combine
- Combine highest tasks
- Compare tasks
- Convert z-scores
- Copy
- Deciles
- Elective weight
- Grade average
- Grade cut-off
- Grade number
- Grade percentage
- Grade weight
- Linear Scale
- Linear mapping
- Moderate
- Quartiles
- Range
- Rank
- Round
- Standardise
- Weight
Average calculation
A task with an average calculation stores the average of the selected tasks. With this calculation, average means converting the results in each task to a percentage, and averaging these percentages for each student.
The average percent for each student is multiplied by the task maximum to produce a final result that is shown in the task. The average calculation does not do any standardisation of the results in each task. The final result is a linear sum that takes no account of the distribution of the raw results.
Average highest tasks calculation
A task with an average highest tasks calculation stores the average of the highest results from the selected tasks. You can specify the number of tasks to be averaged and only that number of tasks with the best scores are used to calculate the average. With this calculation, average means converting the results in each task to a percentage, and averaging these percentages for each student.
The average percent for each student is multiplied by the task maximum to produce a final result that is shown in the task. The average calculation does not do any standardisation of the results in each task. The final result is a linear sum that takes no account of the distribution of the raw results.
Combine calculation
A task with a combine calculation stores the total of the selected tasks. With this calculation, combined total means summing the result in each task for each student.
The combined total for each student is linearly scaled to be in the range of zero and the task maximum to produce a final result that is shown in the task. The combine calculation does not do any standardisation of the results in each task. The final result is a linear sum that takes no account of the distribution of the raw results.
If the task has a maximum that is equal to the total of the selected task maximums, the combine calculation gives the same result as adding the raw result for each student.
Combine highest tasks calculation
A task with a combine calculation stores the total of the highest results for the selected tasks. You can specify the number of tasks to be combined and only that number of tasks with the best scores are used to calculate the total sum. With this calculation, combined total means summing the result in each task for each student.
The combined total for each student is linearly scaled to be in the range of zero and the task maximum to produce a final result that is shown in the task. The combine calculation does not do any standardisation of the results in each task. The final result is a linear sum that takes no account of the distribution of the raw results.
If the task has a maximum that is equal to the total of the selected task maximums, the combine calculation gives the same result as adding the raw result for each student.
Compare tasks
A task with a combine calculation stores the difference between the two selected tasks. Each student result in the first task is subtracted from the result in the second task. This is useful for comparing student performance between two tasks.
Convert z-scores
A task with a convert z-scores calculation converts a set of z-scores into a set of marks with the mean and standard deviation that you specify. Each student has their z-score multiplied by the standard deviation and added to the mean.
This is useful if in the Preferences command you have the z-score weighting option of the Calculation defaults Methods set to Yes. By using this calculation you can convert the z-scores to actual marks.
Copy calculation
A task with a copy calculation stores the results from selected tasks. Copy only stores the results from one task for each student. This is useful when there is more than one task with a total that needs to be ranked as a single group.
For example, Class A has three exams that are weighted to a single set of results. Class B, in the same markbook has three different exams that are weighted as separate tasks that produce another set of results. So, there are two tasks each used by a different class for storing a weighted calculation, but for further calculations, the results from each class need to be in a single task.
By creating a new task, and assigning the copy calculation to it you can choose the two tasks that are copied into the single task. The tasks chosen for the copy calculation should only have one result for each student in the selected tasks.
This calculation is useful when working with classes in a single markbook that require different types of calculations but still need to produce a single task of results for ranking purposes.
Deciles
A task with a Deciles calculation stores the decile for each student based on his or her result in the selected task. In this calculation, the decile means assigning the highest decile of 1st to the top 10% percent of students with the highest results. The next 10% percent grouping of students are assigned 2nd, repeating this process until all the students have a decile, from 3rd to 10th.
If two or more students have the same result they are assigned the same decile, even if this means assigning more than 10% percent to the group. To ensure the number of students in each decile is as close to 10% of the total number, you can use the Edit|Decimal places command to show the figures after the decimal point to separate the students if the results are not all whole numbers.
Elective weight calculation
A task with an elective weight calculation stores the weighted total of the selected tasks that may include tasks not done by all students. The weight for each task is specified as part of the calculation and is attached to the task with the calculation.
If a task is missing a result for a particular student that task is ignored for that student and only the tasks that have a result a weighted together. Unlike the regular weight calculation, the elective weight calculation does not produce a N/A if a student has missing results.
With this calculation, weight means standardising the results for each task to a specified mean and standard deviation, multiplying each task by its weight, and summing each weighted task.
The weight percent for each student is multiplied by the task maximum to produce a final result that is shown in the task. The elective weight calculation standardises each task to a set mean and standard deviation that is set in the Options of the Edit|Calculation.
The Calculation method in the Preferences command allows the changing of the mathematical steps used when calculating the mean and standard deviation and the weighted results.
Grade average calculation
A task with a Grade average calculation stores the grade average of the selected tasks. With this calculation, grade average means converting the letter grade in each task to a number, and averaging these numbers and converting them back to a letter grade for each student.
This calculation only works for tasks that have a letter grade in them. Mathematically, A is equal to 1, B is equal to 2 and so on. For each student these numbers are averaged and then converted back to a letter, so if the average is 3 the student is assigned the grade of C.
Grade cut-off calculation
A task with a Grade cut-off calculation stores a grade for each student based on his or her result in the selected task. With this calculation, grade cut-off means assigning the highest grade to the students with results greater than, or equal to the first cut-off. The next grade is then assigned to the students with a result greater than or equal, to the next grade cut-off, repeating this process until all the students have a grade.
The Preferences command allows you to set the initial list of grades shown for this calculation and the cut-off for each one.
Grade number calculation
A task with a Grade number calculation stores a grade for each student based on his or her result in the selected task. In this calculation, grade with set number means assigning a specific number of students with the highest results with the highest grade. The specified number of students get the next grade, repeating this process until all the students have a grade.
If two or more students have the same result they are assigned the same grade, even if this means assigning more than the specified number. The Preferences command allows you to set the initial list of grades shown for this calculation and the percent for each one.
Grade percent calculation
A task with a Grade percent calculation stores a grade for each student based on his or her result in the selected task. In this calculation, grade with percentages means assigning the highest grade to a specified percentage of students with the highest results. The next percent grouping of students are assigned the next grade, repeating this process until all the students have a grade.
If two or more students have the same result they are assigned the same grade, even if this means assigning more than the specified percent. The Preferences command allows you to set the initial list of grades shown for this calculation.
Grade weight calculation
A task with a Grade weight calculation stores a weighted grade for each student. With this calculation the grade weight means converting the letter grade in each task to a number, and weighting these numbers and converting them back to a letter grade for each student. You select the weighting for each task by choosing the Options button.
This calculation only works for tasks that have a letter grade in them. Mathematically, A is equal to 1, B is equal to 2 and so on. For each student these numbers are weighted in a linear way and then converted back to a letter, so if for example the weighted total is 4 the student is assigned the grade of D.
Linear Scale calculation
A task with a linear scale calculation stores the linearly scaled result of a task. In this calculation, linear means first converting the result to a percentage. The percent for each student is multiplied by the task maximum to produce a final result. The linear scale calculation does not do any standardisation of the results in the task.
Linear mapping calculation
A task with a linear mapping calculation stores the mapped results of one task in another task. In this calculation, linear mapping means changing each student result according to a linear formula. It is similar to changing the range, but has more flexibility as more than one set of results can be specified as the mapping points.
If a linear mapping with only two points is required, the Range calculation has the same effect and is easier to use.
Moderate calculation
A task with a moderate calculation stores the standardised result of one task that is moderated to have the same distribution as another task.
In this calculation, moderate means standardising the results for the task to the mean and standard deviation of the same class but in another task. The moderate calculation standardises the first task added to the calculation so each class has the same mean and standard deviation of the second task.
Quartiles calculation
A task with a Quartiles calculation stores the quartile for each student based on his or her result in the selected task. In this calculation, the quartile means assigning the highest quartile of 1st to the top 25% percent of students with the highest results. The next 25% percent grouping of students are assigned 2nd, repeating this process until all the students have a quartile with 3rd and 4th.
If two or more students have the same result they are assigned the same quartile, even if this means assigning more than 25% percent to the group. To ensure the number of students in each quartile is as close to 25% of the total number, you can use the Edit|Decimal places command to show the figures after the decimal point to separate the students if the results are not all whole numbers.
Range calculation
A task with a range calculation stores the linearly mapped result of a task. In this calculation, range means linearly mapping the results so the student with the highest result is mapped to maximum specified value, and the student with the lowest result is mapped to minimum value.
The results between the maximum and minimum are linearly mapped so the relative difference between each student is unaltered.
Rank calculation
A task with a rank calculation stores the ranking of each student on the selected task. In this calculation, ranking students means assigning a 1 to the student with the highest result, a 2 to the next highest, repeating this process down to the lowest result.
If two or more students have the same result, they are assigned an equal rank which is indicated by the = symbol next to the rank. The students are ranked with the results rounded to the number of decimal places shown in the selected task.
Round calculation
A task with a round calculation stores the results from selected tasks. This calculation rounds and stores the numbers, which can be useful, if the results are used in further calculations where the hidden significant figures are unnecessary.
Round allows you to select the number of decimal places to be stored in a column. Normally SM-Marks Online stores results to a minimum of six significant although in the display the results are rounded.
Standardise calculation
A task with a standardise calculation, stores the standardised result of a task. In this calculation, standardise means standardising the results for the task to a specified mean and standard deviation.
The Calculation method in the Preferences command allows the changing of the mathematical steps used when standardising the results.
Weight calculation
A task with a custom weight calculation stores the weighted total of the selected tasks. The weight for each task is specified as part of the calculation and is attached to the task with the calculation this. This means the same tasks can be given different weights in different calculations.
With this calculation, weight means standardising the results for each task to a specified mean and standard deviation, multiplying each task by its weight, and summing each weighted task. The weight percent for each student is multiplied by the task maximum to produce a final result that is shown in the task.
The Calculation method in the Preferences command allows the changing of the mathematical steps used when standardising the results.