To create this type of assignment, you must have an assignment type with the "Bubble" submit method in your Grading Scheme.
Bubblesheet assignments will be denoted with the icon to the left on your assignments page.
Additional Options
Randomize question order: determines whether the questions will appear in the order you set, or be randomized for each student.
Optional Class Instructions: is any additional instructions you want to appear at the beginning of the assignment.
The method of adding questions to an assignment is the same for all assignment types and is explained here.
Once the assignment is ready for students to start working on, you must publish it to the class. This prevents further editing of the assignment, so make sure you mean it. This process is explained in depth here.