Train and retrain the observers. Make sure the observers understand what behaviors to record and how to recognize them when and if they do and do not occur. Familiarize the observers with the...

Train and retrain the observers. Make sure the observers understand what behaviors to record and how to recognize them when and if they do and do not occur. Familiarize the observers with the recording instruments before they start using them. Set up trial periods, say, through role-playing, where the observers get a chance to practice. Give the observers continued training sessions, especially if the intervention program is a long one, to ensure a continuing understanding of the behaviors to be observed (to avoid “observer drift”).