To tell the truth, I think its flat out stupid to refer to a person as your "half brother" or "half sister"..It doesn't matter if you have the same mom and different dads or the same dad and different moms. You're siblings and should always be referred to as that. I wish people would stop this half stuff. All its doing is separating the kids and making them inferior to one another. As parents we must inform our kids that they're siblings no matter what. They are full siblings at that. This transition from using this term starts with us and we need to put it in full effect.