For Jocelyn, the graduate sociology students have become her reference group
A group that is used for comparing with other groups or individuals refers to the reference groups. Reference groups can be divided into four types such as Comparative Reference Groups,Normative Groups, Dissociative Groups and Status Reference Groups. For example the demographic sociologists can compare the behavior of individuals with the reference groups behavior.
In the given situation, Jocelyn evaluates the writing skills of herself with students of the graduate sociology. She compares her writing skills with them. Thus For Jocelyn, the graduate sociology students have become her reference group