See Self-esteem run amok at Adrienne's Corner.My commentary below the fold:
Back in 1996-1997, two edicts about grading papers were issued by the school administration of a private school where I was working:
1. Don't make wrong answer with an "x." because an "x" hurts a student's feelings.
2. Don't use red ink to grade papers because red ink "alarms" students. We teachers were then issued a supply of pens with purple ink.
I defied both edicts, completed my contract, and resigned at the end of the year.