Final answer:
Sociologists study the frequency of contact in social networks to determine if a tie is strong or weak.
Step-by-step explanation:
Sociologists who study social networks and employment pay attention to the frequency with which a person has been in contact with each member of their social network in order to see if a particular tie is strong or weak.
Strong ties in social networks, where a person has frequent and close contact with others, have been found to encourage engagement and activism, while weak ties, such as those formed on social media, limit the level of risk individuals are willing to take for others.
By studying the frequency of contact, sociologists can understand the strength of connections within a social network.