There are plenty of exams that give either partial credit for "I don't know" or negative credit for a wrong answer (to discourage guessing). Training on intern

There are plenty of exams that give either partial credit for "I don't know" or negative credit for a wrong answer (to discourage guessing). Training on internet comments is going to make "I don't know" rather unlikely because when someone asks a question in an online forum and I don't know the answer, people will just not respond rather than responding "I don't know"