Here a user story:
I will create a quiz and set the grades: a max grade, a passing grade and feedback related to several intervals.
I plan to define the max grade to 50.
When setting up a quiz instance I can at first define the passing grade. Well. Ok. But where the hell can I set the maximum grade? I set the passing grade to 35. Thats my plan.
Then I can define the feedback intervals based on percentage. Is the passing grade a number or a percentage? hmm. Ok. I know that feedback is defined based on percentage and I add the data.
Then I will save my definitions. Uups. It doesn't work. Where is the problem? Ah, passing grade can be set to the max of 10 . Is this a general setting or related to the max grade. I don't know. Where the hell can I set the max. grade?
The solution: Define the passing grade onyl when you've created to quiz questions complete.
Go to the quiz editing page where you add the questions , define the maximum grade. Then go back to the quiz setting page and add the correct passing grade. Why the hell should the teacher go back to the settings?
Is it possible to do this in a better way? Is it? I think yes, it is.
Add the max grade definition in the row before passing grade. Let the setting in the question editing page and let them overwrite if you correct at the other place.
Add the passing grade to the question editing page direct below the max grade settings.
I came up to this situation when I answered a users question about quiz grading in German forum here at moodle.org