Researchers use all sorts of techniques to collect data, ranging from very controlled lab experiments to natural observation. With naturalistic observation the researcher allows behavior to occur without interference or intervention at all. We all do this type of research when we do things like people watch. This is a great way to study behavior in "real settings" and to see behavior occur in its most natural state. The problem is that it's often difficult to study the behaviors you're most interested in without being intrusive.