Tim - I received an inquiry from a user confused about why the grade on the quiz review was different from the grade recorded in the gradebook. I had them send me a backup of the course and looked into it. It turned out that the student took an attempt, a teacher went in and changed the marks for a couple of questions from 1 to 0, and did not regrade the quiz attempts. As a result, things were out of sync as demonstrated by some of the attached screen shots.

Looking at a particular example, the student had a quiz attempt which was recorded in the gradebook as an 85 but when looking at the quiz review it showed a score of 90. Both 85 and 90 are incorrect. The issue is that two of the questions were rated as being worth 0 marks (questions 20 and 21 - see quiz_marks.png). Essentially the teacher removed two questions from the quiz by changing the marks for questions 20 and 21. In the original course (prior to regrading), it looks like the attempt review counts the total number of correct responses and divides it by the number of marks. So the review indicates that the student answered 28 correct out of 31 marks for a score of 90 (see quiz_grade_orig.png). I suspect when the student actually took the quiz they saw that they answered 28 correct out of 33 marks (for a score of 84.8 - i.e. 85). Then the teacher changed the marks and now the student views the report and gets the false 90. The regrade will show the correct score of 26/31 which is an 84 (see quiz_grade_regrade.png). Looking at quiz_report.png and quiz_report_2.png is what clued me in to what was going on. Teachers should be aware that they need to regrade the quizzes if they make a change to the question's point/mark value if there are attempts on that quiz in order to avoid confusion and inaccurate grades. As best as I can tell there is no bug; however, since it does open up the possibility for erroneous data to be in the gradebook, I am marking this as a major issue.

I think there are two options, one if the marks change then automatically regrade the attempts. The other, which I see as much simpler and perhaps the better to implement this is remind/alert the teacher that they need to regrade the quiz attempts because of the change in marks. So if changing the marks and if there are attempts on that quiz, then produce the notice. If I get a chance I'll see if I can throw a quick patch together before my retreat starts. Let me know if you have any questions or if I did not explain something clearly.

Peace - Anthony