C.6 Design and apply discontinuous measurement procedures (e.g., interval recording, time sampling)
In applied behavior analysis (ABA), sampling procedures are used to collect data on behavior within a given time period. Two commonly used sampling procedures are interval recording and time sampling. Here’s an explanation of each and examples:
Interval Recording
Interval recording involves dividing the observation period into a series of intervals and recording whether the behavior of interest occurs or does not occur within each interval. It provides an estimate of the proportion of time that the behavior is observed.
Example: Let’s say a behavior analyst tracks a child’s on-task behavior during a classroom session using 1-minute intervals. At the end of each minute, the analyst records whether the child was on-task or off-task. If the child is on-task for at least 30 seconds within each 1-minute interval, the interval is marked as “on-task,” and if the child is off-task for more than 30 seconds within the interval, it is marked as “off-task.”
In applied behavior analysis (ABA), various sampling procedures are used to collect data on behavior. Three commonly used sampling procedures are partial interval recording, whole interval recording, and momentary time sampling. Here’s an explanation of each, along with examples, benefits, and weaknesses.
Partial Interval Recording
Partial interval recording involves dividing the observation period into intervals and recording whether the behavior of interest occurred at any point during each interval. It provides information about whether the behavior occurred at least once during the interval.
Example: A behavior analyst is observing a child’s hand-raising behavior in a classroom setting using 1-minute intervals. At the end of each minute, the analyst records whether the child raised their hand at any point during that minute. If the child raised their hand at least once during the interval, it is recorded as a positive occurrence.
Benefits
- Relatively easy and quick to implement.
- Useful for behaviors that have a high frequency or rapid occurrence.
- Allows for an estimate of the presence of the behavior during the observation period.
Weaknesses
- May overestimate the occurrence of the behavior if it happens only briefly within each interval.
- Does not provide information about the duration or frequency of the behavior
Whole Interval Recording
Whole interval recording involves dividing the observation period into intervals and recording whether the behavior of interest occurred throughout the entire duration of each interval. It provides information about whether the behavior was continuously present throughout the interval.
Example: A behavior analyst is observing a child’s on-task behavior during a classroom session using 5-minute intervals. The analyst notes whether the child remains on-task for the entire 5 minutes. If the child is on-task for the entire interval, it is recorded as a positive occurrence.
Benefits
- Provides a conservative estimate of the occurrence of the behavior.
- Useful for behaviors that require sustained engagement or continuous presence.
Weaknesses
- May underestimate the occurrence of the behavior if it occurs only briefly within each interval.
- Does not capture occurrences of the behavior that happen between intervals.
Time Sampling
Time sampling involves selecting specific time points or intervals during the observation period and recording whether the behavior of interest is occurring at that moment. It provides information about the presence or absence of behavior at selected time points.
Example: Suppose a behavior analyst is observing a group of children engaging in cooperative play. The analyst uses a time sampling procedure of 10-second intervals. At each interval, the analyst quickly scans the group and records whether any instances of cooperative play are occurring. If cooperative play is observed at any point during the 10-second interval, it is recorded as present, and if not, it is recorded as absent.
Momentary Time Sampling
Momentary time sampling involves selecting specific time points or intervals during the observation period and recording whether the behavior of interest is occurring at that particular moment. It provides information about the presence or absence of the behavior at specific time points.
Example: A behavior analyst is observing a child’s social interactions during a play session using 30-second intervals. At the end of each interval, the analyst quickly determines whether the child is engaged in social interactions. If social interaction is observed at any point during the interval, it is recorded as present.
Benefits
- Efficient and less time-consuming compared to continuous measurement.
- Suitable for behaviors that have low-frequency occurrences or brief durations.
Weaknesses
- May underestimate the occurrence of the behavior if it happens only briefly within each interval.
- Does not provide information about the duration or frequency of the behavior within the interval.
It’s important to choose the appropriate sampling procedure based on the behavior being observed, the goals of the assessment, and the available resources. Each method has its strengths and weaknesses, and behavior analysts should consider these factors when selecting the most appropriate sampling procedure for their specific needs.
Both interval recording and time sampling procedures are used to efficiently gather data on behavior within limited observation periods. They are suitable when continuous measurement is not feasible or practical. These sampling procedures allow behavior analysts to obtain representative data and make reliable judgments about the occurrence or absence of behavior. The specific sampling procedure chosen depends on the behavior being observed, the goals of the assessment, and the available resources and time constraints.