Quiz Password
As long as the quiz is available/visible to students, they can complete that quiz anytime and anywhere. If you want to prevent them from taking the quiz outside of your class, you can require a quiz password. The password can be anything you type into that box.
A few tips:
You may opt to change the quiz password between class periods so that a kid in your 1st period doesn't text that password to kids in later periods in order for them to take it early. As soon as all kids in that period have entered the quiz, you can change the password; this mean you do not need to wait for everyone to submit the quiz since the change will take effect once a new attempt has started.
Having a password is especially helpful on retests. You could require students to come to tutorials or complete their required work before you give them the retest password.
Quiz Time Limit
The time limit will begin as soon as a student has pressed "start attempt" on their quiz. Setting a time limit on a quiz has several benefits:
It provides a max amount of time that students have to complete the assessment. This creates an urgency that isn't there with an otherwise "unlimited" amount of time.
It adds a countdown timer to each student's quiz so that students can manage their own time.
It automatically submits the quiz once that time has expired. Without a time limit, a student's attempt will show as "in progress" without a grade until that kid manually submits their quiz.
Students with accommodations: If you have students who need extended time, you can duplicate the quiz and adjust the settings on the duplicated version to allow for extra time (example 45 minutes instead of 20). Then, you can restrict access to that extra time quiz so that only the designated students can access it.
Require Sequential Answering
Want students to answer questions in order and not return to a previously answered question?
This is a quiz setting that can be adjusted. The default setting is a "free" navigation method which allows students to answer questions in any order and return to any question before submitting the quiz. When this default is changed to "sequential" for the navigation method, students must answer the questions in order that they appear within the quiz and they are prevented from going backwards to look at earlier questions that have already been answered.