Discontinuous Measurement in ABA: Complete Guide with Types, Implementation, and Real-Life Examples

August 28, 2025
Discontinuous measurement is a key ABA tool.
It tracks behavior without constant observation.
Used when full observation isn’t practical.
This guide covers types, setup, and examples.

In Applied Behavior Analysis (ABA), data collection is key to understanding and improving behavior. Sometimes, recording every single instance of a behavior isn’t possible this is where discontinuous measurement ABA comes in. Instead of tracking behavior all the time, it samples behavior in parts, giving us useful information without needing constant observation.

Key Takeaways:

  • Discontinuous measurement is less precise than continuous tracking but still provides meaningful data.
  • It is often used when behaviors happen too often or sessions are too long to record everything.
  • Common methods include partial interval, whole interval, and momentary time sampling.
  • The main trade-off: easier data collection but less accuracy compared to continuous measurement.

What is Discontinuous Measurement in ABA?

Discontinuous measurement (also called time sampling or interval recording) is a method used in ABA to estimate how often a behavior happens by sampling parts of time, rather than watching and recording every moment.

In this approach, you divide an observation session into smaller time intervals, and during each interval you note whether the target behavior occurred (or occurred all the time, or at a specific moment).

Because you’re sampling, this method is more practical in real settings (like classrooms or long sessions) when continuous measurement might be too hard to maintain.

However, discontinuous methods introduce some measurement error:

  • Some techniques tend to overestimate how often behavior happens (e.g. partial interval recording).
  • Others tend to underestimate it (e.g. whole interval recording)
  • Momentary time sampling has a more balanced error profile but still has limits.

Because of that, when possible, continuous measurement is preferred for more accurate data, especially in research or when precision matters.

But in many applied settings, discontinuous measurement is often the more realistic choice.

Why Use Discontinuous Measurement in ABA?

Discontinuous measurement in ABA is a valuable tool in Applied Behavior Analysis (ABA) for several reasons. It offers efficiency, making it ideal for busy therapists or educators who juggle multiple responsibilities. It also reduces the observer's burden, enabling meaningful data collection without requiring constant observation. This approach is particularly feasible in group settings such as classrooms, therapy groups, or home environments where continuous monitoring is not always practical.

When It’s Most Appropriate:

Discontinuous measurement works best for behaviors that occur frequently or last for extended periods of time. It is also well-suited for environments where the observer needs to multitask or in situations where exact counts are less critical, but identifying behavioral trends is essential.

"It can be time-consuming and redundant to use continuous data collection for behaviors that happen very frequently. With careful planning, teachers and RBTs can collect discontinuous data on multiple students while managing the class effectively."
- April Torres, M.Ed., BCBA

Types of Discontinuous Measurement in ABA

In Applied Behavior Analysis (ABA), there are three main methods used to measure behaviors: Partial Interval Recording, Whole Interval Recording, and Momentary Time Sampling. Each method has its own rules, advantages, and limitations.

1. Partial Interval Recording (PIR)

Partial Interval Recording is a discontinuous measurement method where the observer marks “yes” if the target behavior occurs at any point during a set time interval. If the behavior doesn’t occur, it’s marked “no.” For example, if the interval is 5 minutes, and the behavior happens for just 10 seconds, it still counts as a “yes.” PIR provides a quick way to see whether a behavior occurs, but it does not capture how long it lasts or how many times it happens.

When to Collect Partial Interval Recording Data in ABA

  • Best used for frequent or high-rate behaviors that occur often throughout a session.
  • Works well when the behavior is disruptive and the goal is reduction (e.g., shouting out answers, pacing).
  • Less useful for rare or long-lasting behaviors, since the method may distort the actual picture.

How to Visualize ABA Partial Interval Recording Data

  • Line graphs: Plot the percentage of intervals with behavior across sessions to see progress over time.
  • Bar charts: Compare occurrence across different settings (e.g., classroom vs home).

Examples of ABA Partial Interval Recording

  • Tracking whether a student leaves their seat at any point during each 2-minute interval.
  • Recording if a child calls out without raising their hand during any part of a 5-minute interval.
  • Monitoring self-stimulatory behaviors (e.g., hand-flapping, tapping) in short intervals.

Pros and Cons

Pros

  • Simple to implement with minimal training.
  • Efficient for high-frequency behaviors that are difficult to count continuously.
  • Provides a quick snapshot of whether a behavior is happening at all.

Cons

  • Overestimates behavior because even one brief instance in an interval counts as “yes.”
  • Doesn’t show frequency (how many times) or duration (how long) within the interval.

2. Whole Interval Recording (WIR)

Whole Interval Recording is a discontinuous measurement method where the observer marks “yes” only if the behavior occurs for the entire duration of a set time interval. If the behavior stops, even briefly, it’s marked “no.” For example, if the interval is 5 minutes, the behavior must last for all 5 minutes to count as “yes.” This method highlights whether a behavior is sustained, but it may underestimate how often behavior actually occurs.

When to Collect ABA Whole Internal Recording Data

  • Best used for durational behaviors that you want to increase (e.g., staying on-task, sitting quietly, reading).
  • Works well for positive behaviors you want to encourage and extend in length.
  • Not ideal for behaviors that occur in short bursts, since even brief interruptions will count against it.

How to Visualize Whole Internal Recording Data

  • Line graphs: Show the percentage of intervals where the behavior lasted the full time, useful for tracking growth in sustained behaviors.
  • Stacked bar charts: Helpful if measuring multiple positive behaviors (e.g., time on-task vs. time off-task).

Examples ABA Whole Internal Recording Data

  • Recording if a student stays seated for the entire 10-minute interval.
  • Tracking whether a child reads silently for the full duration of each 5-minute interval.
  • Observing if a learner remains engaged in a group activity without leaving until the interval ends.

Pros and Cons

Pros

  • Useful for building and strengthening long-lasting positive behaviors.
  • Highlights improvements in maintaining a skill or activity.
  • Encourages goals around sustained engagement.

Cons

  • Underestimates behavior because even a short pause or interruption results in a “no.”
  • Not appropriate for high-frequency, short-duration behaviors.
  • May overlook partial successes (e.g., sitting for 4 out of 5 minutes still counts as a failure).

3. Momentary Time Sampling (MTS)

Momentary Time Sampling (MTS) is a discontinuous measurement method where the observer checks whether the behavior is happening at the exact end of each time interval. The observation session is divided into equal intervals (e.g., every 2 or 5 minutes). At the end of each interval, the observer looks up to see if the behavior is occurring right at that moment. If it is, they mark “yes”; if not, they mark “no.”

This method provides quick snapshots of behavior, but because it only checks at specific times, it may either overestimate or underestimate how often the behavior truly happens.

When to Collect ABA Momentary Time Sampling Data

  • Best for behaviors that last for longer periods, such as being on-task, staying seated, or participating in group play.
  • Works well in group settings where constant observation isn’t realistic.
  • Useful when staff need to balance data collection with other duties.

How to Visualize Momentary Time Sampling Data

  • Line graphs: Show the percentage of intervals where the behavior was observed at the sample moment, helpful for tracking progress over time.
  • Pie charts: Provide a simple snapshot of how often the behavior was present vs. absent across the session.

Examples Momentary Time Sampling Datain ABA

  • Checking every 5 minutes to see if a student is writing in their notebook.
  • Observing at 10-minute marks to record if a child is still engaged in cooperative play.
  • Monitoring a group of students by scanning at the end of each interval to see how many are on-task.

Pros and Cons

Pros

  • Easier for observers does not require continuous monitoring.
  • Practical in busy classrooms or clinical settings.
  • Can be used with multiple learners at once.

Cons

  • May miss short, quick behaviors that occur between checks.
  • Accuracy depends on how intervals are timed.
  • Provides only snapshots, not a full picture of the behavior pattern.

Choosing the Right Method

Goal Recommended Method Why
Increase on-task behavior Whole Interval Recording Encourages sustained attention.
Reduce brief, unpredictable behaviors Partial Interval Recording Captures even short instances.
Monitor behavior in group settings while multitasking Momentary Time Sampling Efficient and less intrusive.

How to Set Up Discontinuous Measurement in ABA

Implementing discontinuous measurement in ABA requires planning so that the data collected is reliable and consistent. Here are the main steps:

  1. Define the Target Behavior
    • Write the behavior in simple, observable, and measurable terms (e.g., “raising hand” instead of “being attentive”). Clear definitions reduce errors across observers.
  2. Choose the Right Measurement Method
    • Select Partial Interval Recording (PIR), Whole Interval Recording (WIR), or Momentary Time Sampling (MTS) depending on your goal:
      • PIR: captures any instance within the interval, often overestimates behavior.
      • WIR: requires behavior to last the entire interval, often underestimates behavior.
      • MTS: records whether behavior happens at the exact moment of the check, balancing convenience and accuracy.
  3. Set the Interval Length
    • Base this on the frequency and duration of the behavior.
      • Short intervals (e.g., 10–30 seconds) give more accuracy for quick behaviors.
      • Longer intervals (e.g., 1–5 minutes) may work for behaviors that last longer or happen less often.
  4. Decide on the Observation Period
    • Choose a session length that reflects typical conditions (e.g., a 1-hour classroom block).
    • Plan consistent intervals (e.g., 10-minute checks during the session) to ensure data is evenly distributed.
  5. Prepare Materials
    • Use data sheets, timers, clickers, or digital apps for consistent tracking. Some ABA software can automate prompts and recording, reducing human error.
  6. Train Data Collectors
    • Ensure all observers understand the behavior definition, recording rules, and timing procedures.
    • Conduct practice sessions to check for interobserver agreement (IOA) before starting.
  7. Pilot Test Your System
    • Run a short trial to confirm interval length, observation period, and recording method are practical and reliable. Adjust as needed.
  8. Begin Regular Data Collection and Review
    • Collect data consistently across sessions.
    • Review data trends often to evaluate accuracy and make instructional decisions.

Tools for Data Collection 

For discontinuous measurement, you’ll need tools that make recording simple and reliable:

  • Data Sheets – Printable sheets for PIR, WIR, or MTS with clear intervals and checkboxes.
  • Digital ABA Software – Platforms like Theralytics can automate intervals, reminders, and graphs.
  • Timers or Alarms – Stopwatches, phone timers, or vibrating watches help keep intervals accurate.
  • Clickers or Tally Counters – Handy for quick marking during sessions before transferring data.

The right tool depends on your setting, paper sheets work for simple sessions, while software saves time in busy clinics.

How to Analyze the Data 

Once data is collected, the next step is turning numbers into useful insights.

  1. Visual Analysis
    • Graphing is standard in ABA because it makes patterns easier to see.
    • Line graphs are often preferred for showing changes over time, while bar graphs can help compare across sessions or conditions.
    • Look for trends in frequency or duration, stability of the behavior, and shifts when interventions are applied.
  2. Identify Patterns
    • Pay attention to when the behavior occurs most often (e.g., mornings vs afternoons, structured tasks vs free play).
    • This can reveal environmental triggers or conditions that make the behavior more likely.
  3. Interpret with Caution
    • Discontinuous measurement methods (PIR, WIR, MTS) estimate behavior and can over- or under-represent what actually happened.
    • For example, PIR tends to overestimate, while WIR tends to underestimate true levels of behavior.
    • Because of this, always consider the measurement method’s limits before making decisions.
  4. Apply Findings
    • Use the data to guide treatment plans; adjust reinforcement, teaching strategies, or environmental supports.

Examples in Real Life 

  • PIR (Partial Interval Recording): Tracking how often aggression happens in a busy classroom. 
  • WIR (Whole Interval Recording): Measuring how long someone stays focused, like reading without stopping. 
  • MTS (Momentary Time Sampling): Checking if a student is on-task every 5 minutes during group work. 
  • Parents: Watching if a child follows bedtime rules at specific times. 

How To Make Sure Data Is Reliable (IOA) 

Reliability in data collection is essential in ABA, and the standard way to check this is through Interobserver Agreement (IOA). IOA measures how consistently two or more observers record the same behavior during the same observation period. High agreement means the behavior is clearly defined and the data can be trusted.

  1. How It Works
    • Two trained observers collect data on the same behavior, at the same time, using the same method (PIR, WIR, or MTS).
    • Their records are compared to calculate the percentage of agreement.
  2. Acceptable Standards
    • In practice, 80% or higher agreement is generally considered acceptable, though research standards often aim for 90% or higher to ensure accuracy.
  3. Why It Matters
    • High IOA increases confidence that data reflects the actual behavior and not observer bias.
    • Low IOA signals the need to refine the behavior definition, provide more observer training, or adjust the measurement system.
  4. Methods of Calculating IOA (for discontinuous measurement)
    • Interval-by-interval agreement: compare each interval for a match (commonly used with PIR/WIR).
    • Scored-interval agreement: focuses only on intervals where at least one observer recorded the behavior (avoids inflating agreement when behavior is rare).
    • Unscored-interval agreement: focuses on intervals where at least one observer did not record the behavior (helps with high-frequency behaviors).

Conclusion

Discontinuous measurement in ABA is a practical way to track behavior when continuous recording isn’t possible. While it doesn’t capture every detail, it provides valuable insights that can guide treatment and help identify behavior patterns. The key is choosing the right method for your goal, defining behaviors clearly, and ensuring that data is reliable.

Key Takeaways:

  • PIR is best for capturing frequent, short behaviors.
  • WIR is best for sustained positive behaviors.
  • MTS is best for efficiency in group or multitasking settings.
  • Always define behaviors clearly, choose appropriate intervals, and ensure IOA.

By applying these strategies, you’ll make discontinuous measurement ABA both effective and meaningful for behavior analysis.

FAQ

What interval length is best for discontinuous measurement ABA?
Shorter intervals usually give more accurate data, while longer intervals reduce effort but may lower precision. The right interval depends on the frequency and duration of the target behavior.

Can I switch between different discontinuous measurement ABA methods?
Yes. You can move from Partial Interval Recording (PIR) to Whole Interval Recording (WIR) or Momentary Time Sampling (MTS). Just make sure to document the change so results aren’t misinterpreted.

Is discontinuous measurement ABA acceptable for insurance purposes?
Sometimes. Certain payers allow discontinuous data collection, especially for group or high-frequency behaviors. However, many insurers prefer continuous data, so always check requirements with your funding source.

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