Measuring Behavior: Interval Recording/Time Sampling
Interval Recording (or Time
Sampling) involves observing whether a behavior occurs or does not occur
during specified time periods. Once the length of an observation session is
identified, the time is broken down into smaller intervals that are all equal
in length. A watch, stopwatch, or other device is used to keep track of
intervals. Observer calculates the % of intervals in which the behavior
occurred. There are 3 distinct types, defined below.
Advantages: -Useful for high-rate behaviors that are difficult to count -Useful for behaviors with no clear beginning or end -Observations can be brief (10 mins+) or longer periods of time -Translates to a percentage that can be easily plotted on a graph to visually inspect changes in the behaviors Disadvantages: -Only provides an estimate of the behaviors -Provides a sample, may not be representative -Usually requires outside observer & undivided attention -Requires a time keeping device 3 types of Interval Recording: Momentary Time Sampling - Mark if the behavior is exhibited at the precise moment of the end of the interval - May underestimate behaviors - Easiest to collect data on multiple behaviors - May take peer data at the same time for comparison - Useful for very frequent behaviors that last for longer periods of time Whole Interval Recording - When interval ends, mark if behavior exhibited for the entire interval - Underestimates behaviors - Requires undivided attention - Useful for ongoing behaviors that will continue across intervals Partial Interval Recording - Mark if behavior exhibited at any time during the interval - May overestimate behaviors - Requires undivided attention - Useful when behavior happens so quickly it’s hard to catch Adapted from University of Kansas http://www.specialconnections.ku.edu/?q=assessment/data_based_decision_making/teacher_tools/partial_interval_recording |