Setup Add the following line inside the function mod_quiz_calculate_question_stats in mod/quiz/lib.php. (last function in the file) error_log ( __FUNCTION__ . ' called' ); Open a terminal and tail your web server's error log. e.g. in Ubuntu tail -f /var/log/apache2/error .log Test As a teacher create a quiz with a simple true/false question As a student attempt the quiz Submit the attempt As a teacher open the question bank for the course containing the quiz Verify on the error log that the function `mod_quiz_calculate_question_stats` is called when loading the question bank page As an admin go to site administration -> Plugins -> Question bank plugins -> Manage question bank plugins Click on the eye symbol next to Question statistics to disable them As a teacher open the question bank for the course containing the quiz Verify on the error log that the function `mod_quiz_calculate_question_stats` is not called when loading the question bank page