I have a course with an overall aggregation type of 'Weighted mean of grades'. I have two course categories both using a 'Simple weighted means of grades'. One of the course categories is worth 70% of the total course weight, with the other category is worth 30%. I have a created a scale with four values (No activity, Minimal expectations, Meets expectations, Exceeds expectations). The problem is that the actual values for the scale go from 1-4, rather than 0-3 as I would like it. From everything I'm reading in moodle docs, the scale scores should be 0-3, since the aggregation type is a normalized type (Simple weighted mean of grades) rather than a Sum aggregation method. However, the scale starts with the value 1 rather than 0. Any ideas what I might be doing/interpreting incorrectly?
Scale scores start at 1, so your 1-4 scale is as it should be. You can easily offset it to 0-3 by setting the Offset in the grade item to -1. hth 
EDIT:
Nop, that was too hasty. Offset doesn't seem to work with scales.
Until the scale engine is rewritten (2.0 ???) you may have to work around or with formulas.
EDIT:
Nop, that was too hasty. Offset doesn't seem to work with scales.
Until the scale engine is rewritten (2.0 ???) you may have to work around or with formulas.
Hi David,
May be you can post screenshots of the grader report and categories and items?
it seemed to work for me - the first item was treated as 0%.
Was this something you were looking for, like on my creenshot?
May be you can post screenshots of the grader report and categories and items?
it seemed to work for me - the first item was treated as 0%.
Was this something you were looking for, like on my creenshot?
Interesting. The percentage of scale items actually goes from 0 to 100. Makes sense I guess. And it is also a good practice in general to work on 0-100 scale anyway (or at least one scale which can always be normalized to percentage).
yep, moodle gradebook just loves percentages, so I always advise people here to display them to make sense out of the grades, letters, scales, and calculations they have 
Thanks very much for your feedback/support Itamar and Elena. I did a bit more fiddling and it now seems to be working the way it should. I should have been a bit more systematic in my fiddling, as I cannot retrace what I changed, but you're quite right Elena, it does work correctly. 
