Partial-Interval Recording
Also called: PIR, partial interval, discontinuous measurement
Definition
A discontinuous measurement procedure in which an observation period is divided into equal intervals and the behavior is scored as occurring if it happens at any point during the interval, regardless of duration or number of occurrences. It systematically overestimates the true occurrence of behavior.
In plain language
You split the session into short blocks. If the behavior happens at all during a block, you mark that block. One quick moment counts the same as the whole block, so this method tends to make behavior look more frequent than it is.
Examples
In ten-second intervals, a learner shouts once at second three. That interval is scored, and the count moves on.
A plan tracks hand flapping in one-minute intervals across a thirty-minute session and reports the percentage of intervals scored.
Not partial-interval recording
Counting each separate instance of shouting as it happens. That is frequency recording, which is continuous rather than interval based.
Scoring an interval only when the behavior lasted the entire interval. That is whole-interval recording.
Commonly confused with
Written from
- baer-wolf-risley-1968 — Measurement of applied behavior
Written from standard measurement practice in applied behavior analysis. No textbook glossary consulted or paraphrased.
This entry has not yet been through clinical review. Treat it as a draft.