This article is from the Training Your Dog FAQ, posted to rec.pets.dogs newsgroup. Maintained by Cindy Tittle Moore with numerous contributions by others.
In contemporary dog training, a lot of attention is paid to operant conditioning -- "clicker training" is nothing more or less than the real-world application of one small part of Skinner's research. But classical conditioning is almost always present, and should be kept in mind: think about the dog who hears the bell -- his drooling represents the kind of happy anticipation that we want in a working dog. Classical conditioning, in its practical application, is all about training for attitude. If he associates good stuff (positive reinforcement) with training situations (think of that as the bell ringing) he'll show the same kind of eagerness that you'd expect if you extrapolate from Pavlov's droolers. In addition, even with operant conditioning on a dog, you will eventually associate a command with the behavior, so that you can elicit the bahavior from a stimulus! Such a sequence would be:
1. dog offers behavior (say a sit)
2. dog is rewarded
3. cycle continues until dog continually offers behavior
4. trainer now says "sit"
5. dog sits
6. dog is rewarded
which combines elements of both operant and classic conditioning.