In psychology of learning there are four types of contingencies. The four different types are positive reinforcement, negative reinforcement, positive punishment, and negative punishment. These contingencies are a part of operant conditioning that helps either reinforce and influence or punish and diminish a particular behavior. When discussing positive reinforcement, this is when there is a factor added into the situation to reinforce the behavior. Negative reinforcement is just the opposite; a factor is removed to help reinforce the behavior. In positive punishment, there is a factor being added to help decrease a particular behavior. Whereas negative punishment is removing a factor to help decrease behavior.