Moodle Quiz is a best way to evaluate the students understanding about the learning in your course. Few months ago, someone asked in Moodle forums about displaying “just those questions that were answered incorrectly on the previous attempt” if ‘when each attempt builds on the last’ is selected as the question behavior in quiz settings.
Currently there is no visual ways to display which questions were correct/wrong on subsequent attempts due to which it is very difficult for the students to concentrate only on the incorrect answers of previous attempts. So based on the forum discussion, a new Tracker issue is raised MDL-53802 to display correct/wrong on subsequent attempts.
The tracker issue seeks that in case of subsequent attempts, the quiz navigation buttons should display the correct and incorrect question numbers with colored background like Green for correct answer and Red for incorrect Answer; which is by default Grey in color.
If you would also like to add this feature to the Moodle Quiz engine, then please vote for the Tracker issue at MDL-53802.
Do let us know what are the other features and improvements which you would like to have in Moodle quiz in comments below.