Nowadays there's a small but growing body of research on why dogs bark, what they might mean when they do, and who understands that meaning. Researchers have concluded that dogs have different barks for different circumstances, that dogs respond differently to different barks, and that humans as young as ten years old are pretty good at deciphering barks, even when they can't see the dog.
But there's a gap between what scientists care about and what owners of barking dogs care about. Plug "stop barking" into Google and on just the first page of more than half a million results you'll see ads for a "bark eliminator," a "dog silencer," and an "ultrasonic bark control." Next time you're held captive in an airplane seat, thumb through SkyMall to see devices like these pictured alongside remedies for life's other little annoyances, like electronic cellulite smoothers and replicas of the One Ring. How likely do you think it is that such solutions take into account why a dog might be barking?
Clicker training takes a different approach. You may never truly know why a dog barks, but relying on the principles of behavior analysis, you can make a pretty good guess. With that information, it's possible to change behavior in a way that improves the quality of the dog's life as well as the owner's.
The goal of the training described in this article is the reduction of excessive barking in a given situation, not the elimination of barking from your dog's repertoire. It's unrealistic, and unfair, to expect a dog never to bark. Many of my clients, when asked to consider it, actually appreciate some of the barking their dogs do. Barking can warn that a stranger is on the premises, announce that it's potty time, or express excitement at the prospect of a ball flying into a lake.
If your dog's barking is part of a larger pattern of fear or aggression or has begun suddenly with no major environmental changes, or if you truly cannot identify a pattern in your dog's barking, consult your veterinarian to rule out medical causes before embarking on a training program. Barking primarily while left alone may be a sign of separation anxiety, and should also be brought to the attention of your vet as soon as possible.