The concept of motivating operation deals with the observation that behavior depends not only on the stimuli present in the current situation and the organism's past experience with those stimuli, but also on the organism's recent past history of deprivation, satiation, pain, or other such influences. Such a past history can have two effects: it can change the value of a consequence by making it more or less reinforcing, and/or it can change the probability of behaviors that have produced that consequence. For example, food deprivation changes the value of food, making it more reinforcing, and it also evokes learned behaviors that have obtained food. Likewise, food satiation reduces the both the reinforcing effect of food and the probability of food-getting behaviors.