How does it work?
The penis is removed from the vagina before ejaculation (loss of seminal fluid into the vagina).

How effective is it?
The effectiveness rate is 81% to 96% depending on if the man knows when he is going to ejaculate. Its effectiveness is also greatly diminished, due to the fact that most men secrete a fluid known as pre-ejaculate, or pre-cum, before they actually ejaculate. While this doesn't have as much sperm in it as the actual ejaculation, it still has enough in it to cause a pregnancy.

What's good about it?
It does not harm your body in any way. Your partner learns more about how his body works.

What's not good about it?
It is not very effective for many people. It may take a while to learn the control needed for this method. It does not protect against sexually transmitted infections.