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Momentary Time Sampling and Data Collection


We were recently observing a student working and he had the right pieces in place – classroom rules, behaviour contract, etc. but his lack of attending was really interfering with his ability to keep to the rules and get his work done, especially in the classroom. Even with positive behaviour supports in place, there was no real way to track whether he was on task or not.  Tracking attending can be challenging because it’s hard to know exactly when off-task behaviour starts and stops. Frequency and duration would not be the most accurate data collection methods.  Therefore, we developed a momentary time sampling data sheet to track and teach on-task behaviour.

What is Momentary Time Sampling?

Momentary time sampling is a sample of the defined behaviour in the exact instant that you’re taking data.  The observer would define the interval of time, let’s say 5 minutes, and look up at the end of the interval.  At the 5-minute mark, the observer would record whether the behaviour is occurring or is not occurring.  THE LEARNER DOES NOT HAVE TO ENGAGE (OR NOT ENGAGE) IN THE BEHAVIOUR FOR THE ENTIRE INTERVAL. It’s simply a measurement of the behaviour at the end of the interval.   Taking this kind of data will give you a number of intervals in which the behaviour occurred.  Then, you’re looking to either decrease or increase the number of intervals that the behaviour is occurring in. 

Why Use Momentary Time Sampling?

This data collection method is great for behaviours that are not easily counted.  If you’re measuring on-task behaviour, it’s hard to know when one ends and another one starts.  Momentary time sampling allows for a less-intrusive way of collection data that would give you a number of intervals during which the behaviour is occurring.


For the student we were working with, we used a momentary time sampling to track on-task behaviour.  We defined the behaviour(s) we were looking for and made those clear to the student (in the most observable and measurable terms as possible).  Then, every 5 minutes, the therapist would glance up and decide whether the student was on/off task and mark accordingly. By the end of the session, we could calculate a percentage of on-task intervals out of total intervals.


Involve the student in the data and provide reinforcement for when he reaches the daily mastery criteria.  If the target is to be on-task for 60% of the time, then the student would get reinforcement for reaching that target.  This is a great way to teach the student about self-reflection that could eventually lead into self-monitoring one’s own behaviour.

The Teaching Component – Increase Expectations

If you were training to run a marathon, you would start with training yourself to do 1 mile and taking data accordingly.  But you wouldn’t stop there!  As soon as you’re able to do 1 mile in a certain amount of time, you would change your target to more miles or shorter amounts of time and continue to push yourself until you can run the entire marathon.

It’s often not enough to track behaviour, there has to be a teaching component as well.  With this data collection method, you can increase or decrease the desired behaviour by increasing or decreasing the mastery criteria as the student becomes more successful (aka, changing criterion design).  For behaviour you want to increase, once you’re learner has reached mastery for 3 consecutive times, increase mastery to a higher level.  So if the student is able to be on-task for 60% of the time for 3 days, then increase the target by 5%.   If you’re working on decreasing a behaviour, then decrease the target by 5% when the student reaches mastery criteria.  This changing criterion design allows the learner to get better over time.

Be Realistic

When choosing mastery criteria, be realistic.  Know your learner and know what’s doable.  In targeting on-task behaviour, it’s completely unrealistic to expect 90-100% attending because no one is on-task 100% of the time!  Start with a baseline and choose a goal that is achievable.  The nice thing about this kind of method is that since the student only has to meet criteria at the end of the interval, it does allow for some self-correction within the interval.  If at minute 3:30 the student is off-task and is able to get back on task by minute 5, it would still be a successful interval!

Watch our YouTube video on Momentary Time Sampling with Groups!

2 thoughts on “Momentary Time Sampling and Data Collection”

  1. Hello
    I noticed there is a typo in your description of Momentary Time Sampling.
    It should said “DOES NOT”.
    Nonetheless, great, simple, explanation! Thank You!!

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