How is unscored interval IOA calculated?

The calculation of unscored interval Interobserver Agreement (IOA) focuses on the intervals where the behavior does not occur. In this method, the agreement is not based on the total occurrences, but rather on the intervals where both observers agreed that the behavior did not happen.

The correct approach is to take the number of intervals where both observers agreed that the behavior did not occur and divide it by the total number of intervals in which the behavior did not occur at all. This is then multiplied by 100 to express it as a percentage. This method specifically captures the agreement in terms of non-occurrence, which provides a comprehensive understanding of agreement beyond merely scoring intervals of occurrence.

The other options presented either do not align with the unscored interval IOA calculation or focus on the overall occurrence of behavior rather than its non-occurrence. This makes it essential to distinguish the correct calculation method to ensure the accuracy of observer agreement in data collection practices.