Final answer:
A collection of people who share emails about coaching grade-school soccer teams represents a 'group' within social studies. These individuals share a common interest and engage in regular interactions, making them more than a mere aggregate or mass.
Step-by-step explanation:
A collection of people who share e-mails on the subject of coaching grade-school soccer teams is an example of a group. This concept falls under the study of social structures and collective behavior in social studies. Such a group would be categorized based on its members interacting with some frequency, sharing a sense of aligned identity, and often common interests or goals related to coaching. In contrast to a mass or a public, this group's defining feature is the regular interaction among its members, which centers around the activity of coaching.
Various examples supporting this definition are observed in different types of social gatherings: teachers who are part of teachers' unions, staff members involved with the PTA, or political discussion groups. All these instances involve people brought together by shared interests or ideas, and they engage in regular interaction.
In the scenario provided, these individuals not only share a common interest in soccer coaching but also choose to communicate regularly about it via email, thus forming a distinct group within the larger category of people involved in grade-school sports.