Frequency
Frequency is the number of times a behavior occurs during an observation period, recorded by counting every occurrence from start to finish.
Frequency, also called count, is the simplest continuous measure. The RBT makes a tally, presses a clicker or taps a data app each time the target behavior happens, and adds up the total at the end of the observation. It fits behaviors that have a clear beginning and end and do not last long, such as hitting, raising a hand, requesting an item or throwing materials.
A count means little unless the length of the observation is recorded with it. Ten requests in 15 minutes and ten requests in 3 hours are very different levels of behavior. When observation periods vary from session to session, the count is converted to rate (count divided by time) so that sessions can be compared. Note that some textbooks use "frequency" to mean rate; on the RBT exam, read the question to see whether it is asking for a raw count or a count per unit of time.
Frequency is a poor choice for behaviors that last a long or variable time (crying, being out of seat, staying on task), because one 20-minute episode and one 5-second episode would each count as "1". It is also hard to use when the behavior happens so fast that individual responses cannot be told apart, such as rapid hand flapping. In those cases the supervisor may choose duration or an interval method instead.
Example and non-example
| Example | During a 30-minute snack routine, an RBT makes a tally mark every time a teenager signs "more" and writes the total, 12, along with the observation length. |
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| Non-example | An RBT starts a stopwatch when a child begins crying and stops it when the crying ends. That is duration, not frequency. |
Don't confuse it with
Test yourself
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Question 1During a 45-minute small-group lesson, an RBT makes a tally mark each time a 9-year-old raises their hand to answer. Which measurement procedure is the RBT using?
Show answer
C: Frequency recording. Making a mark for every occurrence of a behavior is frequency (count) recording, also called event recording. It suits hand raising because each raise has a clear start and end.
- A: Duration recording would time how long each hand raise lasts rather than count them.
- B: Latency recording would time how long the student takes to respond after a cue.
- D: Whole interval recording would mark only intervals in which the hand stayed up the entire time.
Task A.1 · 40-hour curriculum section C
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Question 2A client's sessions vary from 30 to 90 minutes. The supervisor wants to compare hitting across sessions. Besides counting each hit, what must the RBT record?
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A: The length of time observed in each session. A count from a 90-minute session cannot be fairly compared with a count from a 30-minute session. Recording the observation time lets the count be turned into a rate (count divided by time), which can be compared.
- B: Knowing who was nearby can be useful context, but it does not make counts from sessions of different lengths comparable.
- C: Percentage of intervals comes from a discontinuous procedure; it is not something added to a count to make sessions comparable.
- D: Where a hit lands describes its form, not how often hitting occurs over time.
Task A.1 · 40-hour curriculum section C
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Question 3An RBT counts 18 mands during a 30-minute session. What is the rate of manding?
Show answer
B: 0.6 mands per minute. Rate is the count divided by the observation time: 18 mands ÷ 30 minutes = 0.6 mands per minute (the same as 36 per hour).
- A: 0.3 would result from dividing 18 by 60, but the session lasted 30 minutes.
- C: 1.67 is 30 divided by 18, which is minutes per mand, not mands per minute.
- D: 18 is the total count for the whole session, not the count per minute.
Task A.1 · 40-hour curriculum section C
Answer every question to see your score.
On the RBT exam
This term belongs to task A.1 Continuous measurement in content area A, Data Collection and Graphing, which is 13 of the 75 scored questions.