I created a rubric with several levels of criterion for an assignment. The total number of points possible is 22, and the minimum number of points is zero. I have some levels that at 1/2 of a point, and the rest are whole number integers. But at the top of the rubric (moodle automatically generated it) is the following:
"The minimum possible score for this rubric is 0.5 points and it will be converted to the minimum grade available in this module (which is zero unless the scale is used). The maximum score 22 points will be converted to the maximum grade.
Intermediate scores will be converted respectively and rounded to the nearest available grade.
If a scale is used instead of a grade, the score will be converted to the scale elements as if they were consecutive integers."
The problem is that the minimum score is NOT 0.5 points. It is zero.
I narrowed this down to a small bug in moodle, but I am not a programmer, so I can't fix it. The bug is that this statement derives its information ONLY from the first line of the rubric. But in fact, there are other lines of criterion that do indeed go all the way down to zero. Once I changed the first line to be zero, then the statement above corrected itself.
If you want to reproduce this error, make a simple rubric. Make one criterion (the first one) start with 0.5 as the minimum. Make the second one have a minimum of zero. The statement at the top of the rubric (viewable to students) will tell them that the minimum points is 0.5, but it is, in fact, zero.