Out of this vast reservoir of personally-unknown others, the average human being in his lifetime encounters-actually shares immediate time and space with-only a minuscule proportion. These are the persons of whom we can possess simple categoric knowledge. And these are the persons who are meant when I speak of strangers. … In this more restricted sense, then, a stranger is anyone personally unknown to the actor of reference, but visually available to him.

DEFINE: Schutz defines 'stranger' in a restricted, technical sense as someone personally unknown but visually available, narrowing the everyday meaning for analytical purposes.

DEFINE: Goffman restricts the sociological sense of 'stranger' to persons visually available but personally unknown, excluding the vast reservoir of people one never encounters.

Lyn H. Lofland, World of Strangers_ Order a…, loc. 110