A note on the scaling method you use to combine your tasks

‘Out of’ scaling is the most common and most simple scaling method to use when combining tasks. It will simply produce a final mark out of the number you specify. It will also allow you to indicate the weights of each task. By using this method, you are indicating that each task has been well marked and the spread of marks is appropriate - that is, there is no need to adjust the average or spread of marks.

However, if you do want to eventually scale your final mark to standardise things like the average and spread of marks, it may be better to select the scaling method you are going to use as you combine.

If you do this, iWise will come up with the final mark in this way:

a)	First iWise will scale the component tasks using the specified scaling parameters (eg: it will set a new top and a new bottom mark on each individual task);

b)	Then the new task scores will be combined together, using the specified weights; and then

c)	The combined result will be re-scaled using the specified scaling parameters.

This will remove any bias in the component tasks when producing the weighted final result.

An example where scaling will work better than just setting a new 'out of' value:

You are combing 3 tasks:
Task 1 has an average of 30% and a standard deviation of 3 (low scoring, low spread)
Task 2 has an average of 60% and standard deviation of 12 (nice spread and mark)
Task 3 has an average of 50% and standard deviation of 18

If you want to weight these three tasks equally, but don’t pre-scale them (with a new mean and standard deviation for example), then Task 1 won’t count for nearly as much (because it has low marks and a low spread) as Task 3 (which has a high spread).