Final answer:
The interaction known for involving people known only in their partial roles is called role-based interaction. This type of interaction is guided by the behaviors that are culturally expected of someone in a specific role, and these expectations inform the individual's conduct in different contexts.
Step-by-step explanation:
The pattern of interaction characterized by knowing many people, but only in their partial roles is best described as role-based interaction. This concept relates to how individuals in society adhere to the patterns of behavior that are expected of them in specific settings or groups. In role-based interactions, individuals act in accordance with culturally shared knowledge about what behavior is expected of a person in a given role, such as a student, employee, or family member. These expectations can dictate behavior to such an extent that one's identity and personality may seem to vary according to the different social groups and contexts they are part of.
For instance, the behavior of a person as a child attending a family function will likely differ from how they act as an employee at work. In sociology, researchers who adopt the Symbolic Interactionist perspective focus on these daily interactions and group dynamics, studying the details of how social roles and behaviors vary and influence one another within various settings and groups.