Lots of special education professionals put themselves and their programs in danger of due process by failing to collect accurate, objective data to prove that an intervention is successful. Too often teachers and administrators make the mistake of thinking it is enough to blame the child or blame the parents. Successful interventions (see BIP's) need the appropriate means of supplying data to measure the success of the intervention. For behaviors you wish to reduce, the interval observation is an appropriate measure.

## Operational Definition

The first step of creating an interval observation is to write down the behavior you will be observing. Be sure it is an operational description. It should be:

- Value-neutral: A description should be "leaves seat during instruction without permission" not "Wanders around and annoys his neighbors."
- Descriptive of what the behavior looks like not feels like: It should be "Kenny pinches his neighbor's arm with forefinger and thumb," not "Kenny pinches his neighbor to be mean."
- Clear enough that anyone who reads your behavior can accurately and consistently recognize it: You might want to ask a colleague or a parent to read your behavior and tell you whether it makes sense.

## Observation Length

How often does the behavior appear? Frequently? Then maybe a shorter period of observation may be sufficient, say one hour. If the behavior appears only once or twice a day, then you need to use a simple frequency form and identify instead what time it appears most frequently. If it is more frequent, but not really frequent, then you may want to make your observation period longer, as much as three hours. If the behavior appears frequently, then it might be useful to ask a third party to do the observation, since it is difficult to teach and observe. If you are a push in special education teacher, your presence may change the dynamic of the student's interactions.

Once you have chosen the length of your observation, write the total amount in the space: Total observation length:

## Create Your Intervals

Divide the total observation time into equal length intervals (here we included 20 5 minute intervals) write down the length of each interval. All intervals need to be the same length: Intervals can be from a few seconds long to a few minutes long.

Check out this free printable pdf 'Interval Observation Form'. Note: Total observation time and length of intervals need to be the same each time that you observe.

## Using the Interval Observation

## Prepare for Data Collection

- Once your form is created, be sure to record date and time of observation.
- Make sure that you have your timing instrument available prior to beginning your observation, be sure it is appropriate for the interval you have chosen. A stopwatch is best for minute intervals.
- Keep an eye on your timing instrument to keep track of the intervals.
- During each time interval look to see if the behavior occurs.
- Once the behavior occurs, place a checkmark (√) for that intervalIf, at the end of the interval the behavior did not occur, place a zero (0) for that interval.
- At the end of your observation time, total the number of checkmarks. Find the percentage by dividing the number of check marks by the total number of intervals. In our example, 4 intervals out of 20 interval observations would be 20%, or "The target behavior appeared in 20 percent of observed intervals."

## Behavior IEP Goals that Would Use Interval Observation.

- In a classroom, Alex will reduce the incidence of off-task behaviors (tongue clicking, hand flapping, and rocking) to 20% of observed intervals in three out of four consecutive one-hour observations as recorded by classroom staff.
- In the general education classroom, Melissa will remain in her seat in 80% of observed intervals in three out of four consecutive one-hour observations taken during instructional time by classroom staff.