Prerequisite: Create a test course with more than 1000 students. Hint - generate a small (S) test course using the generator admin tool (Site administration -> Development -> Make test course) but change the number of users in the file:  admin/tool/generator/classes/course_backend.php from: private static $paramusers = array(1, 100, 1000, 10000, 50000, 100000); to: private static $paramusers = array(1, 1200, 1000, 10000, 50000, 100000); As a teacher go to an assignment in the course.  Go to the grading interface (grading a single student, not view all submissions).  In the user selector in the top right of the screen, click the down arrow to display the list of users. Verify that after a few seconds delay, a list of 100 users is displayed. Scroll the list down to the bottom with the mouse. Verify that the last option is "View more" Click on the last option. Verify that after a short wait, the list displays more users (1000 now). Verify that the list is scrolled to the start of the new users. Scroll the list down to the bottom with the mouse. Verify that the last option is "View more" Click on the last option. Verify that after a short wait, the list displays even more users (all of them now). Verify that the list is scrolled to the start of the new users. Verify that the last option no longer displays as "View more". Verify that each time "View more" is clicked, the rest of the page does not change because no real user was selected. Reload the entire page. Click in the User selector. Type a string matching only a few users. e.g. "emma davis". Verify that only a short list of "Emma davis" users is selected and no "View more" option is available. Delete all text from this field and press the down arrow to display a large list of users again. Move down the list using the arrow keys and verify the last option is "View more". Select the last option and press enter to select it. Verify the list of users is refreshed after a short delay and works the same as clicking on the 'View more' option.