ABA therapy relies on data to understand behavior, measure progress, and determine whether teaching strategies are working. But that does not always mean a therapist records every instance of a behavior from the beginning to the end of a session.
Sometimes, behavior is measured during specific periods or at particular moments. This approach is known as discontinuous measurement.
Discontinuous measurement in ABA is a method of collecting data by observing and recording behavior during selected intervals rather than continuously throughout an entire observation period. ABA professionals can use this information to identify patterns and track changes in behavior over time.
What Does Discontinuous Measurement Mean in ABA?
With continuous measurement, data is collected each time a behavior occurs during the observation period. A therapist might count every instance of a behavior, record how long each occurrence lasts, or measure the time between events.
Discontinuous measurement takes a different approach. The observation period is divided into smaller intervals, and the observer records whether a particular behavior occurred based on the measurement method being used.
Because the behavior is not recorded continuously, the resulting data provides a sample of what happened during the observation period rather than a record of every occurrence.
Three common discontinuous measurement methods used in ABA are:
- Partial interval recording
- Whole interval recording
- Momentary time sampling
Each method collects information differently and can be useful for different types of behavior.
What Is Partial Interval Recording?
Partial interval recording measures whether a behavior occurs at any point during a set interval.
For example, suppose a BCBA wants to understand how often a child leaves their seat during a 20-minute activity. The observation period could be divided into one-minute intervals.
If the child leaves their seat at any point during an interval, that interval is recorded as an occurrence. The behavior only needs to happen once during the interval to be counted.
Partial interval recording can be useful when the primary question is whether a behavior happened during an interval rather than exactly how many times it occurred or how long it lasted.
However, because an entire interval is marked when a behavior occurs even briefly, partial interval recording can overestimate how much of the observation period the behavior actually occupied.
What Is Whole Interval Recording?
Whole interval recording records a behavior only when it occurs throughout the entire interval.
For example, a therapist might observe whether a child remains engaged with an activity for each 30-second interval. The interval would only be marked if the child stayed engaged for the full 30 seconds.
If the child stopped participating for part of the interval, that interval would not be counted.
Because the behavior must occur for the entire interval, whole interval recording can underestimate how much the behavior actually occurred.
This method can be useful when tracking behaviors that someone wants to increase, such as remaining engaged with an activity or participating in an appropriate routine.
What Is Momentary Time Sampling?
Momentary time sampling records whether a behavior is happening at a specific moment, usually at the end of a predetermined interval.
Imagine that a therapist is observing a child during a classroom activity and checking their engagement every two minutes. At each scheduled moment, the therapist records whether the child is engaged.
The therapist does not need to continuously observe and record the behavior throughout every two-minute interval. Instead, data is collected at those specific moments.
Momentary time sampling can make data collection more practical when continuous observation would be difficult, particularly in settings where a provider is also teaching, interacting with the child, or monitoring other activities.
Continuous vs. Discontinuous Measurement in ABA
The main difference between continuous and discontinuous measurement is how much of the behavior is directly recorded.
Continuous measurement involves recording the target behavior throughout the observation period, such as how often it occurs, how long it lasts, or how much time passes between specific events.
- Frequency: How many times the behavior occurs
- Duration: How long the behavior lasts
- Latency: How much time passes between an instruction or event and the beginning of the behavior
- Interresponse time: How much time passes between two occurrences of a behavior
Discontinuous measurement samples behavior during selected intervals or moments instead.
Neither approach is automatically better in every situation. The appropriate measurement method depends on the behavior, the environment, and what information the BCBA needs to make treatment decisions.
Why Do ABA Professionals Use Discontinuous Measurement?
Continuous data collection can provide detailed information, but collecting it is not always practical.
Some behaviors occur frequently or happen for long periods, making it difficult to record every occurrence while also providing therapy. In other situations, a therapist may be teaching skills, providing prompts, delivering reinforcement, or interacting with the child at the same time.
Discontinuous measurement provides another way to gather useful information while keeping data collection manageable.
A BCBA can choose a measurement method based on factors such as how often the behavior occurs, how long it lasts, where the observation takes place, and what information is needed.
What Are the Limitations of Discontinuous Measurement?
Since discontinuous measurement involves sampling and not documenting every instance of behavior, some information may be missed.
Different methods can also affect how the data appears. Partial interval recording can make a behavior appear more prevalent than it actually was, while whole interval recording can make it appear less prevalent.
Momentary time sampling can miss behaviors that occur between observation points.
These limitations are relevant since behavior analysts use the information derived from the data for intervention purposes. When making recommendations on behavior intervention plans, BCBAs should take into account how a particular measurement method represents information.
What Does Discontinuous Measurement Look Like During ABA Therapy?
The parent will have no role to play in choosing what form of measurement will be done in ABA therapy with their child. The BCBA decides what measurement will be done depending on the behavior or skills that will be measured.
For example, one child’s treatment plan might track participation during a learning activity using whole interval recording. Another behavior could be monitored with partial interval recording, while frequency data might be used for a different target.
Multiple kinds of measurement may be included in a single treatment plan because different behaviors may require different types of measurement.
How Does Data Help Guide ABA Therapy?
Data collection gives a BCBA a way to look beyond impressions such as whether a child “seems to be doing better.”
By reviewing data over time, the BCBA can see whether a skill is developing, whether a behavior is changing, and whether the current teaching strategies are producing the intended results.
When progress is different from what was expected, the BCBA can review the data and determine whether changes to the treatment plan or teaching approach are appropriate.
This ongoing measurement allows the treatment plan to change as the child develops new skills and their needs evolve.
Understanding Your Child’s ABA Treatment
Terms like partial interval recording, whole interval recording, and momentary time sampling can sound complicated. For parents, what matters most is that these are simply different ways your child’s ABA team can track behavior and progress.
The measurement method a BCBA chooses depends on what they are observing and what information will be most useful. Over time, the data can show how your child is progressing, where they may need additional support, and whether changes to the treatment plan could be helpful.
At Cultivate Behavioral Health & Education, each child’s ABA therapy is based on their individual strengths, needs, and treatment goals. If you have questions about how your child’s progress is measured or what to expect during ABA therapy, contact us today to learn more about our services.
