In terms of observer reliability, what is the desired frequency of IOA collection?

In the context of observer reliability, obtaining an inter-observer agreement (IOA) is essential to ensure that the data collected by different observers is consistent and reliable. The desired frequency for collecting IOA should strike a balance between providing a reliable measure of agreement and remaining feasible within the context of ongoing assessments.

Collecting IOA on 20-30% of measurement occasions is considered a best practice. This frequency allows for sufficient data to assess the reliability of observations without overwhelming the observers or making the process burdensome. It helps capture a representative sample of the data collection events, allowing for meaningful evaluations of observer agreement over time.

Having IOA collected at this frequency helps identify potential discrepancies between observers and aids in calibrating their measurement practices, thereby improving the overall quality of data collected in behavioral assessments. Higher percentages, such as more than 50%, while potentially offering more reliability, may be impractical in many settings, especially in continuous or intensive data collection scenarios where maintaining observer attention and efficiency is critical.