"Mistakes corrected are the best evidence of true learning." I thought of this after so many kids asking me for "help" when they hadn't even tried it themselves first. I will not know if you learned anything unless you first try it yourself and then mess up. If I see no evidence of trying and fixing, then I will not help. You must first help yourself. You can not claim to fail by failing to try.
So, I will use my "magnifying glass" to search for mistakes corrected to see if any true learning has happened.