This chapter discusses observation methods for research. It defines observation as using all five senses to systematically monitor both behavioral and non-behavioral activities and conditions. There are two main types of observation: non-behavioral, which includes record analysis, physical condition analysis, and process analysis; and behavioral, which involves nonverbal behavior, linguistic behavior, extra-linguistic behavior, and spatial relationships. The relationship between observer and subject can involve direct or indirect observation, varying levels of concealment, and participant or non-participant observation. Conducting observational studies requires consideration of the type of study, observer training to reduce bias, and developing a detailed data collection plan.