Differential  Reinforcement
of  Other  Behaviors

    One technique of applied behavior analysis that has proven to be useful in decreasing frequent, severe, or repetitive behaviors, especially in those students who are labeled mentally retarded, is known as differential reinforcement of other behaviors (DRO).  DRO is a technique that involves reinforcing (rewarding) a student if an undesired behavior is NOT displayed during a designated time period.  You will differentially reinforce (reward under certain conditions) the absence of the behavior for a certain time period.  The approach is positive in nature in that the student's behavior is either reinforced or ignored.  No punishment is involved.  Although the traditional form of DRO requires a one-to-one teacher-student ratio with independent observers to record data, modifications can easily be made to allow for its use in the classroom, workshop, or home environment.  These modified steps for implementation are presented below.

How to Use DRO

1. Define the behavior of concern in very specific, observable terms.  Be sure that your definition is so precise that others, after reading your definition, will be observing the exact same behavior.
    (for more information, see the link on Behavioral Recording under the "Assessment of Behavior" section on the home page of

2. Conduct a frequency count (see the link on Behavioral Recording under the "Assessment of Behavior" section on the home page of www.BehaviorAdvisor.com)    Figure out how often the behavior occurs on the average per minute/hour/class period?

3. This interval (see step 2) is how long the student must withhold the undesirable behavior in order to be reinforced.  During this time, the student is engaged in normal, everyday tasks.  If a reward other than verbal praise is involved, be sure to tell the student why he is being rewarded each time you do so.

4. If the behavior does occur during the designated time period, tell the student that the time interval is beginning again.  If the student is small or cognitively impaired, restrain that behavior (e.g., hold the head still if rocking; hold the hands still if hand flapping; close the mouth if vocalizing) for two to four seconds and say, "No (name of behavior) . " Or, while restraining, state the behavior you  wish to see (e.g., "Sit still"; "Hands on lap"; "Be quiet").   After you release your restraint, start the designated time period again (or let the time period expire with no reinforcement given).

5. Return to step 2 to monitor progress and determine the length of the next day's time periods.


1. The behavior of concern may occur more frequently for the first day or two.  The rate will then drop drastically.  On the average, intervals will double in length each day.  The behavior usually disappears by the third week.

2.   You may have to decrease instructional time at the beginning of the program in order to deal with the behavior of concern, but you will gain instructional time as the program progresses.

Click here to read an example of how DRO was used


Activities and Discussion Questions

1. Define the following behaviors in specific, observable, and measurable terms. Be very precise.
a. Spits
Click here for one possible definition
b. Curses
Click here for one possible definition
c. Rocking
Click here for one possible definition
d. Throws objects
e. Slams top of desk
f. Turns out classroom lights
g. Leaves work area
h. Screams
i. Hand flapping
j. Bites self
k. Mouthing (Pica)

2. Pretend that you have been observing your students' behavior.  For each of the following examples, figure the designated time period that the undesired behavior must be withheld by the student in order to receive reinforcement.  Here's the formula for figuring the time intervals for DRO:

# of time intervals
----------------------------------       =      The time interval to use for reinforcement
# of times the behavior happened

If Carmen cursed 6 times in 30 minutes, we divide the number of behavior occurrences (6) into the number of time intervals (30).

---        =     The behavior happens about once every 5 minutes (on the average).

Now try this one...
Kanae displayed 15 short "scripting" (reciting dialogue from TV shows or commercials) incidents in a 10 minute observation.

What formula would you use?
CLICK HERE (after you've written down your formula)


Plato says "I want mommy" 75 times in 15 minutes.
What formula will you use?  Write it out.  Plug in the numbers.  Do the work.
So you'll divide the number of time intervals (What number is it?) by the number of times the action happened (What number will that be?).
CLICK HERE (after you've done the figuring)


Fictitious Fact: 5 out of 4 people have a problem with fractions. That's 120% of the population!

OK, you're ready for more...

a. Steve screamed twelve times in fifteen minutes
Click here to see the answer
b. Amber rocked sixteen times in ten minutes (before you restrained her).
Click here to see the answer
c. Cary threw materials on the floor seven times in twenty-five minutes.
Click here to see the answer
d. Rashad bit himself three times in twenty minutes.
Click here to see the answer
e. Dr. Mac told 3 bad jokes in 15 minutes.

3. You find it difficult to keep track of time periods that last thirty-seven seconds, or three minutes and seven seconds, and so on.  What can you do to monitor the behavior accurately while still attending to your other students and tasks?
Click here to see the answer

4. Your student exhibits many undesirable behaviors. How can you deal with more than one behavior at a time?
Click here to see the answer

5. You wish to conduct DRO procedures with many students at once. What can you do to accommodate the different time periods that you calculated for each student?
Click here to see the answer

6. Some of your students' behaviors last a several seconds up to a few minutes. How can you do a frequency count of a behavior that might usually be regarded as best recorded with a duration count (e.g., prolonged humming, rocking, walking)?
Click here to see the answer

7. Have a partner demonstrate an unusual behavior (e.g., screaming, slapping self) while he or she is completing a typical assignment.
a. For three minutes, record the number of behavior outbursts. Do not intervene at this time (except to distract/redirect the student back onto task).
b. Calculate the time period to be used for reinforcement.
c. (Now switch roles)  For three minutes, monitor your partner's behavior while reinforcing him/her and intervening as appropriate to STOP the behavior.  Restart your  time period after either reinforcement or using physical or verbal intervention.  Continue to record the frequency of the behavior during this time.
d. Calculate the new time period to be used for reinforcement.