Comparison issues

I have just started using the comparison feature. I am comparing students attainment grade (which is an average of their test marks - so its a folder) with their target grade. So basically I am asking it to compare one number with another. The problem is that it is giving me the wrong values back. So for example a student has a target of 7 (column B for the comparison) and has achieved an average test score of 5.7 (column A for the comparison). The value the comparison column is showing is -0.2 when it should be -1.3. All of the comparison values are showing the wrong numbers.

I have used a custom grade type for my comparison column which has a max value of 8 and a min value of -8. Passing grade is 0.

What's going wrong? Thanks for any help.

It all depends on the grade types of A, B and the comparison. Make sure they are the same.

It is slightly different if you've assigned your custom grade in A and B as well but I'm assuming you only did so on the comparison.

OK that makes some sense. My issue now is that I dont want attainment or target grades to ever be negative but the comparison can be. I will see what I can do.

Unless you enable the 'cut on max' or 'cut on min' in your grade type the comparison will show the proper negative value.
You can simply disable it or create the same grade type with cuts enabled and a new one without