Dogs, like humans, are hedonistic.  They prefer pleasure to pain. This type of behavior also helps us to survive and procreate.  Operant conditioning is how we teach dogs to respond to our commands.  Let's look at operant behavior.

An operant is a class of responses. That is, the response would generally look the same to an observer but since no two responses are exactly alike we call the response an operant class. Special cases include free operant (Sidman), in which the completion of one response leaves the organism in a position to emit the next.

Operant behavior that can be modified by its consequences and is thus said to be emitted. It has also been called instrumental by B.F. Skinner.

With operant behavior, whether responses occur in the future depend upon the nature of the contingency. To an organism that is hedonistic,  if the stimulus is appetitive (feels good), it is probable that it will occur again (reinforcement). If it is aversive (feels bad), it is not probable that it will occur again in the future (punishment).

Therefore, our actions that may have an effect on the environment can lead to one of these events being added (positive) or withdrawn (negative).

• Positive Reinforcer-
  A stimulus whose presentation increases the probability of responding.
• Negative Reinforcer-
  A stimulus whose removal increases the probability of responding.
• Positive Punishment-
  A stimulus whose presentation decreases the probability of responding.

• Negative Punishment-
  A stilmulus whose removal decreases the probability of responding (that would terminate it)

There are two types of negative reinforcement.

Escape-
When an aversive stimulus is presented and the termination of that stimulus is contingent upon the occurence of a specified operant response. The escape paradogm is S- : R1 » S^o .

Avoidence-
A stimulus is programmed to occur unless a specified operant response occurs which would cancel or postpone the stimulus.  The avoidence paradigm is S^D : R » S^o .

Discriminated Avoidence-
A warning signal precedes the aversive stimulus and a respinse during that stimulus prevents the aversive stimulus on that trial.

Free Operant (Sidman) Avoidence-
No warning signal is arranged and there is no provision for escape.  Each response postpones the aversive stimulus for a fixed period called the reponse-shock (r-s) interval or, in the absence of responding, shocks are delivered regularly according to a shock-shock (s-s) interval.

Premack Principle-
An organism engages in a less desired behavior (like a rat pressing a bar) in order to get the opportunity to engage in a more desired behavior (like eating).