The Simple Way to Understand Motivating Operations (MOs) and Discriminative Stimuli (SDs)
If you're having trouble distinguishing between motivating operations and discriminative stimuli, don't worry, you're not alone! Even experienced professionals in behavior analysis sometimes find these ideas complex. Let’s break them down in a way that’s easier to understand, especially if you work with students or your children at home.
What is a Motivating Operation (MO)?
Motivating operations are situations that make a person want something or not want it. Essentially, MOs change the value of a reinforcer. Think of them as what drives you to seek something or stop seeking it.
Example: Imagine you haven’t had water for two days and you’re in a desert. Suddenly, water becomes the most important thing for you. You are highly motivated to find it. This is an MO: the lack of water has increased its value, and now you want it more than before.
When we use strategies like satiation (when someone has had enough of something) or deprivation (when someone lacks something), we are manipulating motivating operations. These operations change the value of the consequences; in this case, the value of water increases because you are very thirsty.
2 Types of Motivating Operations
Establishing Operations (EO): These make something more desirable or valuable. For example, when you're hungry, food becomes more attractive. If a child hasn't had the chance to play all day, they might really want to play when recess arrives.
Abolishing Operations (AO): These make something less desirable. For example, if you've already eaten a lot of candy, another piece might not seem as appealing. Similarly, if a child has been playing with the same toy for hours, they may lose interest in it.
What is a Discriminative Stimulus (SD)?
A discriminative stimulus is a signal that tells you something is available or accessible. While MOs make you want something, SDs indicate that you can get it.
Example: Let’s stick with the thirst scenario. You’re driving down the road and see a vending machine that says, “Cold Water Available Here.” That vending machine is the SD. It’s telling you that the water, which you now value a lot, is available at that moment and place.
How to Differentiate MOs from SDs?
The key to distinguishing them is simple:
MOs make you want or not want something.
SDs tell you if what you want is available.
Example: Imagine you’re walking through a grocery store feeling hungry. The hunger is the MO because it has increased your desire to eat. Then, you see a sign that says “Freshly Baked Pizzas,” which is the SD, signaling that the food you want is available.
Incorporating MOs and SDs into Behavior Change
When working with students, both MOs and SDs play important roles in behavior.
For MOs: You can manipulate situations to make a child desire a reinforcer more or less. For example, if a child has been playing for a long time, they may no longer want to play. This is satiation. But if you put the toys away for a while, you increase their value later, which is an example of deprivation.
For SDs: Make sure children know when a reward or activity is available. For instance, you could show them a signal indicating it’s time to play or work on a task.
Motivating operations (MOs) change how much we value something, while discriminative stimuli (SDs) tell us when that thing is available. Both are powerful tools in teaching and behavior modification, helping us guide students’ actions more effectively.