In this article, which comprises the second chapter of Studies in Ethnomethodology, Harold Garfinkel offers conceptual and methodological tools to reveal taken-for-granted, obvious, routine grounds of everyday social activities. According to Garfinkel, the most effective and easiest way to explore how ordinary members of the society produce and recognize the commonly known world of daily affairs is a deliberate breaching of background expectancies we rely on in everyday life. It is background expectancies that provides for the recognizability of routine situations as natural, unproblematic, taken-for-granted. These expectancies constitute what is known as “common sense,” and offer to what is happening its character of reality “known in common with others”. If these expectations are not met (as a result of a special procedure), people begin to make efforts to normalize what is happening, which suggest the sociologist how the daily life in society is organized. Through such breaching experiments Garfinkel shows what are the structural grounds of persons’ common understandings in communication and of systematic manifestations of social affects. Analysis of the results of these experiments allows Garfinkel to argue that ordinary member of the society is not a “cultural dope,” i.e. a puppet that dutifully follows social prescriptions and rules, as traditional sociology tends to picture him or her.