In this article, which comprises the first chapter of Studies in Ethnomethodology, Harold Garfinkel considers the basic research principles and policies of ethnomethodology. According to Garfinkel, ethnomethodology starts from the fact that activities whereby members produce and manage settings of organized everyday affairs are identical with members’ procedures for making those settings “accountable”. By “accountable” he means observable-and-reportable, i.e. available to members as situated practices of looking-and-telling. Garfinkel suggests that professional sociology sets as its programmatical task a correction and replacement of indexical (situated) everyday descriptions and actions with “objective” ones, but this task is impossible, since any attempt to “objectify” ordinary actions is itself based on everyday ways to make what happens “accountable”. Citing as an example three ethnomethodological studies (of the activities of Los Angeles Suicide Prevention Center, of the work of sociological coders, and of ordinary conversation), Garfinkel shows that incorrigible indexicality of everyday action is reflective and rational, and therefore can be analyzed on its own as substantive sociological phenomenon. Thus, ethnomethodology is the investigation of the rational properties of indexical expressions and other practical actions as contingent ongoing accomplishments of organized artful practices of everyday life.