This setting determines whether the students can take the lesson more than once or only once.

When the students are allowed to re-take the lesson, the grades shown in the Grades page are either their average grade over the re-takes or their best grade for the lesson. The next parameter determines which of these two grading alternatives is used.

Note that the Question Analysis always uses the answers from the first tries of the lesson: subsequent re-takes by students are ignored.

By default, this option is set to No, meaning that students are not allowed to re-take the lesson.