Final answer:
A group where members are mostly anonymous is known as a secondary group, which is larger and impersonal, in contrast to a primary group which involves closer emotional ties like family and close friends.
Step-by-step explanation:
If an individual belongs to a group whose members are mostly anonymous to one another, that group is almost certainly a secondary group. Secondary groups are often larger and impersonal, task-focused, and serve an instrumental function rather than an emotional one. Examples of secondary groups include a classroom or an office where relationships are more professional and less intimate.
Primary groups, on the other hand, include family and close friends with whom one has long-term emotional engagement. Despite geographical distances, today's technology allows us to maintain these primary group connections. A reference group is a type of group whose values and norms influence an individual's behavior.
Social networks can sometimes bridge the gap between primary and secondary groups, especially online communities with common interests that develop strong ties over time. The lines between these group types are not always clear-cut, as relationships evolve.