Across Subject and Class Calculations

The five predefined calculations that are available in Accelerus, which do not apply on a student-by-student basis but involve class or subject level input, are only available for numeric assessment items. These calculations are:

•

Mean

•

Count

•

Ranking

•	Standardisation

•	Multi-Linear Map

AI CalcTypeRank

They use the raw scores from specified assessment items and store the calculated or moderated result in another item. These results are then available to use in other calculations or to include in student reports.

Where these calculations are referencing results that are blank, contain errors or special values, ie NA, ABS or UG, these are ignored. For example, if there are 30 students in the class, but only 25 have valid results, the Count function will only record 25, and rankings will go from 1 to 25 only, and so forth. The students with non-valid results will have the calculation error text assigned as their result, eg ERR.

Where any of the above functions are used to calculate results across subjects, teachers will not immediately see the calculated results, when working off line in their classes. This is because the calculations rely on all results for the subject and not just those in the teacher’s class. These across-subject calculated results will be displayed in the class file after the teacher updates the class into the Accelerus database. The results displayed, however, will only reflect those saved in the database so far for the subject at the time the teacher updates. and may not be the final calculated scores.

This calculates the mean or average for a class or subject, based on the results of students for a particular assessment item.

All students in the class or subject, as selected, will have the same mean. Therefore, while the mean is not really a result of each student, but of the class or subject, it must be treated as a result of the student in order to be available for insertion in each student’s report.

The Mean function only uses valid results, excluding any students with blanks or any exceptional values that have been defined for the numeric marking scheme for the source item, eg NA.

To set up a Mean calculation:

•	In the Calculation Type dropdown box, select Mean.

•	In the Source Item field, select the assessment item which contains the results for which an average is to be calculated.

Only numeric assessment items will be available for selection.

•	Click either the Subject or Class option, depending on whether you want to calculate a single mean for the whole subject or a separate mean for each class of the subject.

•	Click the OK button.

AI CalcTypeMean

The Count function counts the number of valid results for an assessment item for a class or subject, excluding any blanks or any containing exceptional values defined in the marking scheme of the source item.

Count is mainly used when ranking students, where you may want an out of value, or count of the number of students being ranked, eg Rank 13 out of 65.

To set up a Count calculation:

•	In the Calculation Type dropdown box, select Count.

•	In the Source Item field, select the assessment item which contains the results to be counted.

Any type of assessment item may be counted, not only numerics, with this function.

•	Select your Across option, depending on whether you want to calculate a single count for the whole subject or a separate count per class.

•	Click the OK button.

AI CalcTypeCount

The Ranking function determines the rank order of students in a class or subject on the basis of their results in a particular numeric assessment item. The higher the numeric score, the higher the student is ranked, ie rank 1 is assigned to the highest score.

When students have the same result in the assessment item being ranked, they will receive the same ranking, with the appropriate number of rank numbers being skipped, eg 1, 2, 3, 3, 5, 6.

To set up a Ranking calculation:

➢	Select Ranking from the Calculation Type box.

➢	Select the Source Item, ie the assessment item that contains the results to be ranked. Only numeric assessment items will be available for selection.

➢	Click either the Subject or Class option button, depending on whether you want to rank students across the subject or for each class.

➢	Click the OK button.

AI CalcTypeRank

A Standardisation calculation takes a set of raw numeric results for a class or subject and normalises these to a specified mean and standard deviation.

To set up a Standardisation calculation in an assessment item:

•	In the Calculation Type dropdown box, select Standardisation.

•	In the Source Item field, select the assessment item which contains the results to be standardised. Only numeric assessment items will be available for selection.

•	Click either the Subject or Class option, depending on whether you want to standardise the results across the whole subject or on a class-by-class basis.

•	Enter the Mean, or average, you want to use in the standardisation formula for the subject as a whole, eg 65.

•	Enter the Standard Deviation, eg 12.5, to be used across the subject.

AI CalcTypeStandardise

•	If you have chosen to standardise across classes, you may enter the mean and standard deviation to be used for any of the classes, where these differ from the values to be used for the subject, shown in the Mean and Standard Deviation fields above.

Any class rows left blank will use the subject mean and standard deviation.

•	Click the OK button.

Multi-linear mapping allows you to set the minimum and maximum results for students in a subject and have students’ results recalculated or mapped to other values, according to their relative positions within the minimum and maximum. Optionally, multiple interim points may be mapped within the minimum and maximum.

For example, you may have an assessment item in which the possible result range is 0 to 100. The actual results of students in the subject, however, range from 15 to 88 – the minimum and maximum achieved results, respectively.

You want to map these actual or raw results to another minimum and maximum – say, 25 to 100, so that the students whose result was 15 will now have a mapped result of 25 and the ones with 88 will have 100. You may also want to set two mid-points along the way, mapping 40 to 60 and 75 to 80. This means that there are, in effect, multiple linear mappings – 4 sets in this case.

Other results will be mapped within these ranges according to their relative positions, within each of these mappings.

AI CalcMappings

To set up a Multi-Linear Map calculation:

•	In the Calculation Type dropdown box, select Multi-Linear Map.

•	In the Source Item field, select the assessment item which contains the results to be mapped. Only numeric assessment items will be available for selection.

•	With regards to the Mappings table’s Source MIN and MAX fields:

➢	When in a subject or class results window, the current minimum and maximum results found in the source item will be displayed, or 0 will appear if there are no results in the item yet. The minimum and maximum will change as results are added or changed in the source item.

➢	When adding a multi-linear calculation via a subject's Assessment Items tab, because the results are not available there, the source MIN and MAX will be blank when first setting up the item.

However, once results for the item have been entered or synchronised back into the database, on re-opening the calculation, the current minimum and maximum values stored in the database will be displayed.

•	In the Target cell for the Min row, enter the value you want the raw minimum result for students in the subject to be mapped to.

•	Repeat this in the Target cell for the Max row, for the mapped value of the raw maximum.

AI CalcMultiLinear

•	Optionally, for each point within the minimum and maximum that you want to map:

➢	Click the Add button, and a row will be added between the minimum and maximum rows.

➢	Enter a Source and a Target value, ie the raw value and its mapped value, respectively. For example, 60 may be mapped to 65, 80 to 90, and so on.

AI CalcMultiMappings

•	Delete a mapping row, other than the minimum and maximum rows which cannot be deleted, by clicking in the row to be deleted and then clicking the Delete button.

•	When finished, click the OK button.