Parents

Why do parents try to intimidate teachers with the threat of contacting the administration??

Recently, I had a parent use this because he was unhappy with his daughter's grade. Well, she didn't turn in the work. I notified the child in class that day, and even gave her mandatory tutoring time. Did Dad mention this?  No!  It sounds like there is no communication at home--yet he is calling MY boss???

Please explain!!!!  Thanks!!!