(2) The Formal Group

Generally speaking, the formal group is a kind of group gathered by the work needs. When the work is not needed or finished, the group will be dissolved or adjusted, and people will no longer belong to the group and the relationship will also be terminated. In such a group, the distribution of responsibilities is distributed within the organization. Every member's words and deeds are both subject to the organizational and disciplinary constraints. Their leaders are appointed by the superiors. What’s more, the mass election should also be approved by the higher authorities.

(3) The Informal Group

The concept of the informal group appeared in the late 1920s, and it was first proposed by Professor Mayo, a modern American management psychologist, in his famous Hawthorne experiment. He said that the informal group is spontaneously organized during the interaction among people. Because of the common interests, common feelings, and common goals, they voluntarily get together and finally contribute to the formation of it. The informal group is not as stable and balanced as the formal group, and conversely, it is usually in the condition of continuous adaptation and constant recombination.

Following by the Hawthorne experiment, people have done much more in-depth research on the informal group and they have made various definitions from different angles. Concerning the reasons for its formation, they think that informal group is formed by the emotional needs of people (eg. old classmates, countrymen, people of mutual interests and goals). Once the emotions fade out or break down, their relationship will automatically come to the end. This kind of group is not strictly organized or disciplined, which relies on moral strength to constrain group members' words and deeds, and the most influential person in the group is the leaders who can do whatever he likes without the approval from superiors (Chen Xiaobin, 1999:71). From the aspect of the difference between formal group and informal group, the informal group is the kind of group which sets up without formal official regulation. Actually, this group is a natural product of people who work and live together. There is no provision for the rights and obligations of each member, and it is totally based on its members’ common interests, hobbies, and friendship (He Yunxia, 1987:282). From the factor of group size and formation mechanism, an informal group is a social group gradually shaped by long-term interactions of a certain number of inpiduals (Yu Xianyang, 2001:183). If it is defined on the basis of formation, the informal group is spontaneously formed in the process of communication on the basis of people’s emotion (Lu Jie, 1991:416). 

As a result, the differences between formal groups and informal groups can be clearly seen, but it seems that there is no absolute official stipulation of the informal group. However, combining the different concepts of the informal group from the above scholars, we can conclude that the informal group is a kind of organization that comes into existence naturally in activities without the admission or approval of any authority. It is produced from a sense of belonging among group members with whom they share the same interests and ideas, and their needs and interests are complementary to each other’s as well.

(4) The Informal Group in Middle School

According to the above concept of informal group, this study suggests that the informal groups in middle school are small groups which exist in the class and is formed by those students who share the same or similar interests, hobbies, ideas, or the pursuit of their free interaction, such as self-organized learning groups, activity groups, and chatting groups. These small groups differ from the formal groups in class, like the class committee, team organization, clean duty groups and all other kinds of school extra-curricular activity groups.

The informal group of middle school students is one of the main activity ranges in their daily life interaction and it also becomes an important place for their primary socialization. No matter whether it is for the inpidual member or the formal group, the informal group absolutely has a certain influence on them. This paper focuses on the study of informal groups existing in middle school classes, and those informal groups outside the classes are not included.