When i say time out, i don't mean "isolation" i mean a time out in a place that is quiet where they sit alone with no distractions that is a designated area. This could be in same room with you, in fact its encouraged to stay in same room so you can engage in what they are doing. Also remember, they are only there for the maximum time limited according to their age? Thus if they are 3, then their time out limit is no longer than 3 minutes long.
The child is never alone! But the child needs to learn how to respect authority and when done correctly, it is a case of respect on both ends as this is what adults do with each other when a problem occurs, as they are to walk away until to think things over and get a strategy without angering the situation, and then go back to the person and talk it out. I know at 3 a child will not be able to mentally solve these issues, nor do i think they will be able to have this intellect, but believe me, they do understand what time out means.
I am not saying that time out works for all, and i did say earlier that this was not all of the forms of discipline, but for many children, it does work.
As for the removal pf privileges, it works too, but again, it depends on the child. But i know some who use removal of children's personal items? This is a bit touchy to me. As it makes the child feel like what eve they have is not really theirs as mom or dad have ownership over it anyway, so it makes them feel like a second class person or demeaned somehow?
I guess, it all depends what the circumstances and how old the child is and a lot of factors...This is a question many have asked for a long time. And not sure on the real answer myself as many people have grown up so well in many ways and forms in different aspects.
All i can say is, it sure helps to have the Lord to give us all direction in this area, as without His guidance, i would have pulled my own hair out many a day? LOL