Can I set a quiz to allow students to save and come back to complete it?
By default, quiz questions save automatically after each one is answered. So as long as the quiz is still open and the time limit has not exceeded (if you set a time limit), students can leave and come back in to complete a quiz.
If you have essay questions and plan to have students work on the quiz in pieces, I suggest telling them to "click outside of" the essay questions before leaving. While typing an essay I don't think there is any "trigger" to have it get saved back to the system until you do something else such as answering another question or submitting. So if a student leave the quiz directly from editing an Essay question; the text of that question might not get saved.
At any rate to really answer your question; there is nothing you need to set. Just keep the quiz open an be care about time limits. If there is a 60 minute time limit the clock keeps ticketing even if they leave the quiz.
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