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Whole interval recording is a discontinuous measurement procedure that scores a target behavior as occurring only when it lasts for an entire defined interval. It uses equal time blocks and a strict scoring rule: behavior must be present from the beginning of an interval through its end.
How Whole Interval Recording Works#
Whole interval recording is one type of interval recording in ABA. Interval recording breaks an observation period into equal time blocks and applies a scoring rule to each block. Rather than measuring exactly how long a behavior lasted, the observer records whether each interval met the procedure's criterion.
For whole interval recording, the criterion is continuous behavior across the complete interval. If the target behavior is absent for any part of the interval, that interval is scored as a nonoccurrence.
The RBT Test Content Outline (3rd ed.) states that task A.2 is to implement discontinuous measurement procedures, including partial and whole interval recording and momentary time sampling. For a broader review of the procedure types named in that task, visit discontinuous measurement ABA to compare their scoring rules.
A practical scoring sequence is:
- Read the written definition. Follow the target behavior definition and any stated rules about what counts as an interruption.
- Use the assigned interval length. The written plan determines the length of each interval and the observation period.
- Observe throughout the interval. A whole-interval score requires information about the entire time block.
- Score at the interval boundary. Mark an occurrence only if the behavior remained present without interruption for the full interval.
- Start the next interval. Score each interval separately rather than combining behavior across time blocks.
A helpful reminder is: whole means the whole interval must qualify. “Most of the interval” is not the same as the entire interval.
For definitions of this and related procedures, use the ABA terms hub to find terminology by topic.
Whole Interval Recording Example#
Suppose a written plan defines on-task behavior as looking at assigned materials or writing. An observer uses four consecutive intervals, each lasting ten seconds.
| Interval | Observed on-task behavior | Whole interval score | Reason |
|---|---|---|---|
| 1 | Present from start through end | Occurrence | The behavior lasted throughout the interval. |
| 2 | Present for eight seconds, then stopped | Nonoccurrence | The behavior ended before the interval ended. |
| 3 | Began after three seconds and continued | Nonoccurrence | The behavior was absent at the interval start. |
| 4 | Present from start through end | Occurrence | The behavior lasted throughout the interval. |
Two of the four intervals receive occurrence scores. The observer can report 50% occurrence intervals: two occurrence intervals divided by four total intervals, multiplied by 100.
The grid also shows why whole interval recording provides an underestimate of behavior duration. On-task behavior occurred during parts of intervals two and three, but neither interval qualified for an occurrence score. The result accurately summarizes sustained behavior across full intervals; it does not state the exact number of seconds the behavior occurred.
Use the interval recording calculator when you want to convert completed occurrence intervals and total intervals into a percentage.
Whole Interval, Partial Interval, and Momentary Time Sampling#
These procedures use different rules. The procedure named in the written plan determines what the observer records.
| Procedure | Scoring rule | Typical result |
|---|---|---|
| Whole interval recording | Score behavior only if it occurs for the complete interval. | Tends to underestimate duration. |
| Partial interval recording | Score behavior if it occurs at any point in the interval. | Tends to overestimate duration. |
| Momentary time sampling | Score behavior if it occurs at a designated observation moment. | Summarizes behavior at sampled moments. |
| Duration recording | Measure the amount of time behavior occurs. | Produces a direct time measure. |
What does partial interval recording measure? It measures whether the target behavior occurred at least once during an interval. A brief occurrence and a nearly full-interval occurrence both receive the same occurrence mark under that rule.
The planned partial interval recording page will focus on the “any point during the interval” rule when published. Use the partial interval vs whole interval vs momentary time sampling comparison to distinguish the three procedures now. A separate momentary time sampling page is planned for further review of designated observation moments.
Applying the Scoring Rule Consistently#
Whole interval recording requires the observer to distinguish full-interval behavior from partial-interval behavior. A behavior may be meaningful, frequent, or nearly continuous and still fail to meet the whole-interval criterion for a particular time block.
Behavior begins after the interval starts. Score a nonoccurrence. The behavior was not present for the full interval.
Behavior stops before the timer signals. Score a nonoccurrence. The behavior did not continue through the interval end.
Behavior pauses and resumes. Score a nonoccurrence when the pause counts as an interruption under the written definition.
Behavior continues across an interval boundary. Score each interval separately. The behavior must meet the full-interval rule within each individual block.
The observer checks only at the timer signal. That single observation cannot establish whether behavior occurred throughout the preceding interval. Whole interval recording depends on observing the complete time block.
The written plan supplies the target definition, interval length, and scoring details. The RBT Test Content Outline (3rd ed.) identifies implementation of discontinuous measurement procedures in task A.2. For real-world implementation, follow the supervising clinician's written plan; the RBT Ethics Code 2.0, section 2.02 requires RBTs to follow supervisory direction and accurately document client data.
Practice Questions#
1. During a ten-second interval, Nia remains seated from the start until the timer signals the end. Her written plan uses whole interval recording. What should the RBT record?
A Correct. Nia remained seated for the complete interval described in the stem.
B A nonoccurrence does not match behavior present from the start through the end.
C The written plan specifies an interval score rather than an estimated duration.
D The timer has already ended the interval that needs a score.
2. Omar is on task for the first nine seconds of a ten-second interval, then turns away before the timer signals. His written plan uses whole interval recording. What should the RBT record?
A Nine seconds does not satisfy the full-interval rule because Omar turned away before the end.
B Correct. The interruption in the stem prevents an occurrence score.
C The stated procedure scores each interval separately.
D The plan calls for whole interval recording, not an estimated duration.
3. Priya's written plan uses whole interval recording for writing on her assignment. During a fifteen-second interval, she does not write for the first three seconds, then writes continuously until the timer signals. What should the RBT record?
A The plan uses whole interval recording, and writing was absent during part of this interval.
B Whole interval recording scores the interval described in the stem rather than adding time to another interval.
C Correct. Priya did not write for the complete fifteen-second interval.
D The stated method calls for an interval score rather than an exact duration record.
4. A timer signals the end of an interval. Devon's target behavior was present from the interval's first second through the signal, and the written plan uses whole interval recording. What should the RBT do next?
A The completed interval already provides the information needed for a score.
B The stated procedure requires an interval score, not a duration estimate.
C The behavior was present throughout the interval described in the stem.
D Correct. Devon met the whole-interval criterion, so the interval receives an occurrence score.
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FAQ
What is whole interval recording in ABA?
Whole interval recording in ABA is a discontinuous measurement procedure in which an observer marks an occurrence only when target behavior lasts for an entire defined interval.
What is interval recording?
Interval recording is a measurement approach that divides an observation period into time blocks and applies a stated scoring rule to each block. Whole interval recording, partial interval recording, and momentary time sampling use different rules.
Does whole interval recording overestimate or underestimate behavior?
Whole interval recording tends to underestimate behavior duration. Behavior occurring during only part of an interval is not scored as an occurrence, even if it happened for much of that interval.
Is whole interval recording continuous or discontinuous?
Whole interval recording is discontinuous measurement. It summarizes whether intervals meet a criterion rather than directly recording the exact duration of behavior across the observation period.
When should an RBT use whole interval recording?
An RBT uses whole interval recording when the supervising clinician's plan specifies that procedure. The RBT Test Content Outline (3rd ed.) identifies implementation of whole interval procedures within task A.2, and RBT Ethics Code 2.0, section 2.02 requires RBTs to follow supervisory direction and accurately document client data.