How to Record Single-Subject Research Data

Behavioral recording is a method of evaluating a behavior that provides a researcher with a very precise picture of a behavior’s regularity. The data collector observes a target subject directly and collects data on how long or how often a certain behavior occurs. Using this method, the researcher can compare the degree of occurrence of the behavior with the degree to which it occurs after an intervention is implemented. This can be used to obtain an accurate perception of whether a target subject’s behavior is improving over time.  There are three basic types of behavioral recordings: frequency recording, duration recording, and interval recording (although many other variations are sometimes used for certain purposes). The recording procedure that you choose will depend on the kind of behavior that you plan to measure. Frequently recording or momentary time sampling recording (a type of durational recording) are most commonly used.

Frequency recording is a simple counting of how many times a behavior occurs during a designated period of time. Those designated periods might be a minute, an hour, a day, or a week.  It is most useful with behaviors that are discrete and short in duration. For example, a data collector might record how many times a target subject talked out of turn during a 15-minute class discussion. A researcher trying to reverse a student’s underachievement might record how many homeworks were not submitted over a week.

In momentary time sampling recording, the data collector periodically looks at the target subject at predetermined (NOT spontaneously selected) intervals and records whether a given behavior is occurring. If a researcher were interested in on-task behaviors in a classroom, the data collector might select a 15-minute period and recorded whether the target subject was on or off task at 30 second intervals. At 30 seconds, 1 minute, 90 seconds, 2 minutes, etc. the data collector would mark whether the target subject was on or off tasks and then tally the number of times the target subject was off task over the 15-minute period. The score could range from 0 (never on task) to 60 (off task every time point the data collector checked during the 15 minutes.

With duration recording, you record how long a behavior occurred during predetermined intervals. This is helpful with behaviors that are continuous (last for a given period of time), rather than separate incidents. For example, you might study a dog’s barking behavior. You could count the number of distinct, separate barks (frequency recording) or you could record the length of each barking sequence (duration recording). You might observe the dog for 5-minute intervals. In the first interval, the dog might bark for 20 seconds, stop barking for 2 minutes, bark for 5 seconds, stop barking for 40 seconds, bark for 95 seconds, and then not bark for 20 seconds. If you were frequency recording, you would record 3 for the number of times the dog barked over 5 minutes. If you were duration recording, you would record 115 second for the amount of time the dog barked over 5 minutes.

This material was adapted from material posted at and

Del Siegle, Ph.d.
Posted 2/20/2024