Alphabet Soup



Submitted by: Katy Hudson, BCBA

When I first began my coursework in ABA, my professor stated that this field is very much like alphabet soup in that many terms are shortened into initialisms so it seems that there are just letters floating around. As a parent it can be very daunting when your therapist comes out with your child and states something along the lines of “The data shows the DRO we are using is effective” or “we are using an FR2 schedule and will work up to a VR 5.”, or when you see the weekly summary sheet and see notations like “Mastered 5 LRFFCs, 6 IVs, and 2 LR”. While we try our best to explain what each one of these terms are, it may be helpful to have an overview of some of the terms that are used.


LRFFC – Listener Responding by Feature, Function, or Class. This means that your child is making a choice based on a feature of an item (“Find something red”), a function (“Which one cuts paper?”) or a class (“Where is a vehicle?”). We can also use this to have them make a choice based on all three, for example, “Find a yellow vehicle that takes you places” and the child selects a school bus or a taxi depending on what vehicle is in the array.

IV – Intraverbal. An intraverbal is essentially a response to a statement, answer to a question, or a fill-in-the-blank response. An example of an intraverbals is if I said “How was your day today?” and you stated “It was good!” Another example would be if I said “Twinkle twinkle little….” And you stated “star”. Day to day conversations are also examples of intraverbals.

LR – Listener responding. This means following verbal directions that are given.

Schedules of reinforcement:

FR – Fixed Ratio (commonly followed by a number, i.e. FR4). In the FR4 example this means that for every 4 responses, reinforcement will occur. So if I answered 4 questions correctly, I would then get a token for my token board or something else preferred.

FI – Fixed Interval. This has to do with a passage of time. For example, every 2 minutes I sit on my bottom in the chair appropriately, I would get reinforcement. However, if I got up after 1:30, I would not get the reinforcer because I didn’t make it to 2 minutes.

VR – Variable Ratio. This requires that a variable number of responses occur to receive the reinforcer. So for a VR 5, the responses needed to get reinforcement may be 3,7,4, and 6. These numbers average out to 5 responses (VR5).

VI – Variable Interval. This requires that a variable amount of time pass prior to receiving reinforcement. If we set a VI 2 requirement, the child may need to engage appropriately for 1 minute and then 3 minutes (which averages out to 2 minutes) to receive reinforcement.

Differential Reinforcement:

DRA – Differential reinforcement of alternative behavior. This means that we would reinforce occurrences of a behavior that is an alternative to the problem behavior. For example, we would praise tapping someone’s shoulder gently to get attention rather than hitting that person’s arm.

DRI – Differential reinforcement of incompatible behavior. This means that reinforcement would occur for desired behaviors that are incompatible with the problem behavior. An example of this would be praising a child for sitting in their seat rather than walking around the room. You cannot sit and stand at the same time so this makes these two behaviors incompatible with one another.

DRO – Differential reinforcement of other behavior. This means that reinforcement would be delivered when a problem behavior has not occurred during or at a specific time. For example, if you have gone two minutes without yelling, you would then receive your reinforcer.

While these are not all of the terms that are used in ABA, these are some that are frequently used and discussed with parents. Hopefully this will help in making clearer the alphabet soup that is our wonderful field.