Data Collection Methods
Frequency / Event and Rate Recording
methods involve counting the number of times a behavior occurs in a
specific time period. Use these methods if the behavior can be easily
counted and the behavior has a clear beginning and end. Do not use these
methods if the behavior is occurring at such a high rate that an
accurate count is impossible (e.g., pencil tapping) or the behavior
occurs for extended periods of time (e.g., 2 tantrums, but the duration
of each tantrum is one hour).
Event recording is best for behaviors with a distinct beginning and end.
Event recording has been used to measure behaviors such as:
- Task initiation and protests to task demands
- Inappropriate sitting and littering
Correct and incorrect academic responses
Teachers have used event recording to measure their own behaviors, such as:
recording is best for behaviors that occur with enough in between to
distinguish between the end of one response and the onset of another.
- Praise statements
- Response opportunities provided to students
frequency measure should be used only when the length of observation
time is consistent from day to day (e.g., always 2 hours).
measure should be used if the length of observation time varies from day
to day (e.g., 60 minutes on Monday, 300 minutes on Tuesday).
Summarizing the Data:
At the end of the observation period, total number of occurrences.
For example, Anna left her seat 5 times during 7th period.
Count the number of times the behavior occurred in the time observed.
Divide the count by the length of time the behavior was observed. For
example, if Anna kicked a peer 30 times in a 10 minute observation, the
rate would be 3 kicks per minute (30 kicks divided by 10= 3 kicks per
This method documents the
length of the behavior by recording the time the behavior begins and
ends. Use this method if your primary concern is the length of time the
student engages in the behavior and the behavior has a clear beginning
and end. Do not use this method if the behavior occurs with high
frequency or the behavior starts and stops rapidly.
recording is appropriate for behaviors that have a distinct beginning
and ending or for those that occur at such high rates that it would be
difficult to get an accurate frequency count (e.g., number of taps
during pencil, finger, or toe tapping).
Duration recording has been used to measure behaviors such as:
collecting frequency data for the target behavior in combination with
duration recording to provide a more accurate picture of behavior.
On Task: Looking at the assignment, writing and asking questions
related to the topic, using assigned materials, and following teacher
- Compliance to task demands
- Academic writing tasks
can sometimes be difficult to accurately record the exact duration of
the behavior. On the other hand, duration recording not only tells us
how long the student engages in the behavior, but it automatically
provides us with how many times the behavior occurred.
Summarizing the Data:
Duration can be summarized in two different ways:
of observation with behavior: Sum the total number of min/sec/hrs that
the behavior occurred during the observation, divided the sum by the
total number of min/sec/hrs of the observation, and multiply by 100.
Average Duration of Behavior: Sum the total durations and divide by the total occurrences.
a 60 minute observation, David had 3 tantrums that lasted 3 minutes, 7
minutes, and then 5 minutes with a total duration of 15 minutes. The %
of observation with behavior = 15 minutes divided by 60 minutes= .25
times 100 = Tantrums occurred during 25% of the observation. Average
duration – 15 minutes divided by 3 tantrums = Average of 5 minutes per
recording documents whether a behavior occurred during a particular
period. In order to determine this, an observation period is divided
into brief intervals. At the end of each of these, the observer records
whether or not a behavior has occurred. There are two types of
interval recording: whole and partial interval. When utilizing
whole-interval recording, an observer indicates whether the behavior
occurred during the entire time. (Example: A student worked on an
assignment during an entire thirty-second interval.) When utilizing
partial-interval recording, an observer indicates whether the behavior
occurred at any point during the time interval. (Example: A student
worked on an assignment during fifteen seconds of a thirty-second
interval. The record indicates that the behavior occurred.)
Interval recording is used when it is difficult or impractical to constantly observe behavior.Interval
recording is used for continuous behaviors or for those behaviors whose
onset and end are difficult to distinguish because the behaviors occur
at such high rates.
whole and partial-interval data are reported in terms of the percentage
of total intervals during which the behavior occurred (the number of
intervals the behavior occurred / the number of intervals the behavior
occurred + the number of intervals the behavior did not occur times
- Whole-interval recording yields data on the total duration of the behavior.
- Partial-interval recording yields data on the proportion of the observations period that the behavior occurred.
recoding often takes less time and effort, especially if the behavior
occurs at a high frequency, because the observer records the behavior
only once during the interval, regardless of how many times the behavior
occurs. However, interval recording only provides an estimate of the
actual number of times that a behavior occurs. If the intervals are too
long (e.g., 1 hour), the results can overestimate the frequency of the
behavior. The shorter the interval, the more accurate the
representation of how often the behavior is occurring. For example, if
aggression occurred once per hour in a 5 hour observation, a 1 hour
interval recording form would conclude that the behavior occurred during
100% of intervals (1 occurrence in each 1 hour interval). However, if a
ten minute interval recording for was used, the results would conclude
that the same behavior occurred during only 16.7% of intervals (5 of the
10 minute intervals contained behavior out of a possible 30 intervals).
How to Collect the Data:
the observation period at the times during which the behavior is most
likely to occur. Typically, observations last between ten minutes and
one hour, although it is more accurate and less burdensome to use
1. Divide the observation period into equal intervals. These intervals are usually between five and fifteen seconds long.
Whole interval: Record an “x”, plus sign, or check mark if the behavior
occurred throughout the duration on the interval (e.g., if using
ten-second intervals, the behavior must last the entire ten seconds). If
the behavior did not occur for the entire interval, then record the
nonoccurrence of the behavior with a minus sign or 0. (Note: No more
than one behavior at a time should be observed when using whole-interval
recording, due to the necessity of observing during the entire
B. Partial interval: Record with an “X”, plus sign, or
check mark if the behavior occurred at any point during the interval
(e.g., if using ten second intervals, the behavior must occur at least
once during that particular interval). If the behavior did not occur
during the interval, record the nonoccurrence of the behavior with a
minus or O. (Note: Multiple behaviors can be observed during partial
interval recording because an observer only has to document whether a
behavior occurred at all during an interval.)
2. Count the
number of intervals during which the behavior occurred. Divide this
number by the total number of intervals and multiply by 100 to determine
the percentage of intervals during which the behavior occurred.
Keep in Mind: Interval recording provides an estimation of behavior.
using a prompt to signal the beginning and end of intervals, such as an
audio recording with beeps (headphones should be used!).
- If you
find that you have unmarked intervals, you may have accidentally lost
track during the observation and marked the wrong interval.
Summarizing the Data:
Whole-interval recording typically underestimates the overall
duration of the behavior because if a behavior occurs-but not for the
entire interval- it is not recorded or documented as occurring.
Partial-interval recording typically overestimates the overall
duration and underestimates the rate of the behavior because if a
behavior occurs multiple times during an interval, it is still
documented as occurring only once.
using interval recording, the level of the behavior is reported as the
percentage of intervals in which the behavior occurred. To calculate
the % of intervals, count the number of intervals in which the behavior
was recorded, divide the total number of intervals during the
observation period and multiply by 100.
Example: Mary was out of her
seat during 4 out of 10 intervals. 4/10=.40 times 100= Mary was out of
her seat during 40% of intervals recorded during the observation.