Corporal Punishment

Hi there,

About 5 months ago I transferred to a new branch of the Hagwon where I was employed. I was grateful for the opportunity to move as it was a terrible place to work. I got paid etc but there was iron fisted discipline through the use of corporal punishment. Kids were hit with sticks for reasons such as failure to do homework, failing a test as well as misbehaving. I can understand  misbehaving although I do find this disturbing, I never understood why they hit kids for failing a test. After leaving I discussed this with the new director who was horrified at the thought of kids being hit. Now it's happening at this school on a fairly regular basis.

What I want to know: Is this a legal practice in Korea? 

Even though I have never administered this punishment,  if a parent becomes concerned and uses legal services against the school, am I liable?