First let me say that Mark is amazing, as is the Bark Busters program. My dog had several issues that I wanted to correct, such as; excessive barking, not listening, and aggression. The techniques that are used for training are very easy to follow. My dog started to show improvement during our first session, and it was great seeing results so fast! She has just finished her fifth session and is a totally different dog. Not only is she less dominating, but she is much happier and loyal. She no longer barks, she comes when called, and is able to go on walks without trying to attack every passing animal.