You need to test both the Results -> Grades and Results -> Responses reports for a quiz with several attempt by a number of different students. Create a quiz allowing unlimited attempts, and Highest grade. Add two true-false questions. (Does not have to be TF, but they are quickest.) As Student 1, Make one attempt scoring 50%, one scoring 100%, then start but don't submit a third attempt. As student 2, Submit one attempt. As student 3, don't make any attempts. As teacher/admin, View Results -> Responses Verify 'Show at most one finished attempt per user (Highest grade)' is disabledIf depending on whether Finished is selected above. Run the report for Finished and in-progress attempts, for enrolled users who did, or did not, attept the quiz. Turn on the 'Show at most one finished attempt per user (Highest grade)' option. You should see Student 1 listed twice, and the others listed once. Play with other combinations of options if you like. Now go to Results -> Grades. And repeat steps 7-9. Verify Show only attempts ... that have been regraded / are marked as needing regrading is disabledIf depending on whether 'Enrolled users who have not attempted the quiz' is selected. Select that option, and redisplay the report. Verify that the report is now empty.