A role set is a situation where a single status may have more than one role attached to it. This multiplicity of roles is what sociologists termed it as such. Consider a student

Student

A student is a learner, or someone who attends an educational institution. In some nations, the English term is reserved for those who attend university, while a schoolchild under the age of eighteen is called a pupil in English...

 for instance, involves one role as a pupil

Pupil

The pupil is a hole located in the center of the iris of the eye that allows light to enter the retina. It appears black because most of the light entering the pupil is absorbed by the tissues inside the eye. In humans the pupil is round, but other species, such as some cats, have slit pupils. In...

, another as a user of university library

University Library

University Library refers to academic libraries at universities, such as:*Basel University Library*Cambridge University Library*Cornell University Library*De La Salle University Library*Durham University Library*University of the East Library...

, and another as a member of a faculty

Faculty (university)

A faculty is a division within a university comprising one subject area, or a number of related subject areas...

.

The term "role set" was coined by Robert K. Merton

Robert K. Merton

Robert King Merton was a distinguished American sociologist. He spent most of his career teaching at Columbia University, where he attained the rank of University Professor...

in 1957. He made a clear distinction between a "role set" and a "status set".