Schedules of reinforcement

Reinforcement is anything that increases the possibilities of something to occur. Therefore, if something that is desired is given after a determinate behaviour, it is more likely that the same behaviour will be repeated. But if this reinforcement stops the behaviour will be extinguished eventually.
Behaviourists found that different patterns create a quicker learning or an extinction of a behaviour, named schedules of reinforcement.
The most effective manner of learning, that also provide a slow extinction rate is when the behaviour is  reward randomly, or when the reward is given after an unpredictable amount of time after the behaviour is showed.
On the other hand, the less effective manner is if the behaviour is rewarded automatically every time it occurs, and, in addition,  the extinction rate is fast.

References
McLeod, S. (2015). B.F. Skinner | Operant Conditioning | Simply Psychology. [online] Simplypsychology.org. Available at: http://www.simplypsychology.org/operant-conditioning.html [Accessed 12 Nov. 2015].