An advantage of covert observation is that it should be high in validity, as people are observed in natural surroundings, and – as they are unaware of being observed – the Hawthorne Effect is avoided.

However, a disadvantage of covert observation is that it raises a number of ethical concerns. If people are unaware that they are the objects of sociological study, they have not given informed consent. It might be possible, in some cases, to get consent after the study has taken place, or to receive general consent. Ordinarily deception is required in order to assess the group being observed and, in some cases, there is a risk of illegal or dangerous activities. A famous example of a covert observation is Laud Humphreys' study, ‘The Tearoom Trade’ which included the observation and analysis of men engaging in sexual behaviour in public toilets.