Reinforcers can involve either the addition of a new element or the removal of an element currently present.The terminology for this is a little confusing,but adding something is refered to as "positive" though not necessarily in the sense of "happy" or "good"."Negative in this case,is the removal of something, and does not necessarily mean "bad".Therefore,both rewards and punisers can be either positive or negative.
Giving a parrot a piece of fruit for waving it's foot is addition of something good; a horse moving faster to stop the pressure of spurs is the ending of something bad (negative reward).Evan though "negative reward" sounds like an oxymoron,the removal of something bad is a kind of reward.
Punishers work exactly the same way.When a dog pulls on the leash and gets a sharp tug in the opposite direction,especially when using a choke chain or prong collar,it's a positive punisher or correction;the reviews unpleasant feedback for undesirable behavior.Alternatively,a punisher can be the removal of something good as when a child loses the privilege of going out with friends following misbehavior;thisis a negative punisher.
There are many ways to teach a dog. to set using reinforcer.The trainer may push or lure the dog into a sitting position,or he may simply wait until the dog sits naturally onit's own.Once the dog sits,the trainer may offer a positive reward such as verbal praise ("good boy"),tactile (a pat bad head),a favorite toy, or a treat.Some trainer use negative rewards like electronic collars to administer a mild shock to the dog,which stops as soon as he sits.However ,it follows the same principles of operant conditioning.In every case,the dog will learn that when he hears the command "sits" and he sits,he will get a reward.
Reinforcers can be almost anything as long as they meaningful to the dog.One dog may think treats are more valuable than toys,while another may feel the opposite.It doesn't really matter what the reinforcer is,but for practical reasons,some reinforcers are easier to work with than others.Also,the same reinforcer doesn't have to be used every time or in every situation.Some task may requre a more valuable reinforcer.As pet smart obediance triner Dan O'Leary puts it,"you would probably step over a chair if i offered you a dollar to do it.But you probably wouldn't wash and wax my car for a dollar."Similarly,your dog may work for one type of reward in the relative calm of your home but may need something more desirable to maintain focus in class.