Ethnomethodology is a theoretical approach in sociology regarding the ideology that one can identify social norms based upon one's ability to disrupt it. Essentially, ethnomethodologists identify social norms through an experimentation where they disrupt a known social order in order to see how people will react to the disorder they are seeing. This study also examines what people will do in order to restore order.
A social science professor of mine assigned us the role of enthnomethodologist over one weekend. He wanted us to challenge both unspoken and spoken social order rules and examine how those around us reacted to our breaking of social norms. I choose to sit in a bathroom and talk to people as they came in. As a female, this was not as controversial or challenging as it may have been for a male. Many women openly accepted my conversation, even passing me toilet paper and holding conversations with me from their adjacent stall.
A cohort of mine, male, conducted the same test; although, his experience was far different from my own. He was met with utter shock and silence when trying to "strike" (begin) conversations with the men who entered. Men would either ignore him completely or tell him to mind his own business. When using the restroom, he would try to converse with other men (a known "no-no" in any public restroom situation). Again, he was met with either disgust or cursing.
Both of these experiments examined the breaking of a social norm (not speaking to strangers in a public restroom) and what some people would do to regain the social order (as with being silent or telling the person breaking custom to be quiet, to put it nicely).
Ethnomethodology is a sociological research method in which social norms, practices, and methods are examined. One might apply this concept to using a public restroom by finding the most commonly utilized practices associated with how one approaches using a public restroom, such as wiping off toilet seats before use, "hovering" so as not to make contact with the seat, flushing with one's shoe in order to avoid touching it with one's hand, or using paper towels to grasp door handles. Another example would be adhering to socially acceptable norms such as waiting in line for one's turn or purposefully refraining from eye contact at the men's urinals.