I'm an instructor, and would like the ability to use nested question groups. This way I can have a question group to select a set number of questions -- 10, for example -- but have more than that number of question groups within that group. This would help ensure that when selecting random questions, students will be tested on a number of different topics or concepts, rather than seeing questions that may be repetitive. This would be especially helpful in scenarios when there may be more topics or concepts being tested than quiz questions.