I mean, once teachers add random questions into a quiz and click on the Save button, then the randomly-added quetions should be fixed, hence, every student should see the SAME questions(no longer random questions) in the quiz. This is critical for fairness.
The only work-around I can think of is to buy a set of dice
您好來自中國的Hang Wz Z！
Hello Wz Z from China,
Your question is an interesting one. If I understood it correctly, assuming that you have a category containing many questions, you would like to randomly include some of these questions in a quiz but you would like the questions to be the same for all students. To my knowledge, this is not possible, that is, the students will see different questions.
... every student should see the SAME questions (no longer random questions) in the quiz. This is critical for fairness.
I suggest that you group the questions on the same subject and especially the same level of difficulty in different categories, and create random questions from these different categories. Students will still see different questions but at least these will have the same level of difficulty, which will be fairer for them.
If I was going to do this, this would be my approach. Assume that you have 50 questions in the question bank and want to randomly pick 10. I would use Excel (yes, Tim suggests dice,) and the Excel function RANDBETWEEN(1,50) to have Excel generate some random numbers. Then, in "Edit quiz" mode, I would pick "Add - from question bank" and manually add the questions based upon this randomly created (Excel) list.
To expand on what Dominique said, another approach (in my example) is to create five different quiz categories, with 10 questions in each category, and then create the course quiz based upon a specific quiz category. Expanding this a little further, in the course you could set up five quizzes, each one based upon these five categories, and then randomly assign students to each of these using Moodle's groups.
What it appears you want is a feature that would say something like "Fix these questions for all students once the quiz begins." Quite honestly, I seldom see this kind of request. But it is a genuine request. If you feel strongly about this feature, go to the Moodle Tracker system and create this "feature request." Using the Tracker system is the best place to get the ball rolling (or dice rolling, if you prefer.) Yes, you properly used this Moodle forum, and it is a good place to solicit more ideas and discussion. Reference this forum in Tracker.
Thank you, Tim! Finnally I locate to these 2 files:
I also post here: https://tracker.moodle.org/browse/MDL-67646 But I'm not able to code