<span>The best way to determing who is approaching before seeing them is to rely on other senses. For example, if your uncle never showers then you might be able to smell him even if you can't see him coming. In some cases it may also be possible to tell who is approaching by relying on knowledge about their habits. For example, if someone is coming through the door at six o'clock, and your father usually comes by at that time, then that person is probably your father.</span>
These two researcher obligations, wherein the researchers make sure that the participants are told about the true nature of the study before they leave and they must make sure that the participants do not feel bad about their behavior, are referred to as debriefing and protection from harm.
