When students have a (partly) working solution, they may want to try some other things without affecting the solution to be graded.
Right now, students can only try some things and possibly break their previous solution which they like to retain for grading.
Switching to sandbox mode should be an explicit action where students get aware that things they try won’t affect the last saved solution.

Submitted by Elmer van Chastelet on 28 November 2019 at 07:47