3 Interval Measurement and Time Sampling Free Online FlashCards

What is interval measurement?

It divides an observation into equal time periods and records whether a defined behavior meets a specified scoring rule in each period.

What is the scoring rule for whole-interval recording?

The behavior must occur throughout the entire interval for that interval to be scored positive.

What is the scoring rule for partial-interval recording?

The behavior must occur at any time during the interval, even briefly, for it to be scored positive.

What is the scoring rule for momentary time sampling?

The observer scores whether the behavior is occurring at one specified instant, commonly at the end of each interval.

How do you calculate the percentage of intervals scored positive?

Percentage positive = $\frac{\text{positive intervals}}{\text{total scored intervals}}\times 100$.

What does a percentage of positive intervals represent?

It is the proportion of intervals scored positive under that method, not an exact percentage of observation time occupied by the behavior.

What should you use to measure exact occurrences or total time in a behavior?

Use a suitable continuous measure, such as frequency or duration recording, when feasible.

When is whole-interval recording often useful?

It is often used to measure behaviors intended to continue, such as sustained engagement.

Why can whole-interval recording underestimate behavior?

It tends to underestimate behavior because any interruption makes the interval negative.

How are multiple behavior occurrences scored within one partial interval?

Multiple occurrences in the same interval still count as just one positive interval.

When can partial-interval recording be useful?

It can be useful for detecting behaviors one wants to reduce.

Why can partial-interval recording overestimate behavior duration?

It tends to overestimate how much time the behavior occurred because even a brief occurrence makes an interval positive.