Final answer:
The unscored interval IOA is a measure of agreement between two observers focusing on intervals where a targeted behavior is not recorded by either observer, ensuring reliability in recognizing behavior absence.
Step-by-step explanation:
The meaning of unscored interval Interobserver Agreement (IOA) in the context of behavior measurement refers to the level of agreement between two observers on the presence or absence of a targeted behavior during specific intervals. Option 2 is the correct answer: It is a measure of agreement where only intervals of behavior that are not scored by either observer are considered. This is an important metric in behavior analysis to ensure observers are reliably detecting when the behavior is not occurring, which is as important as detecting when it does occur.
In practical terms, for unscored interval IOA, observers might be watching a video of a classroom and noting when a specific behavior, such as a student raising their hand, does not occur within given intervals. High agreement in unscored intervals suggests that both observers accurately recognize the absence of the targeted behavior, contributing to overall assessment reliability.