1. A group is composed of a number of people who are brought together or who come together voluntarily and who share a common goal, task, or purpose. And then they will deal with it together
2. When people come together in a group, they form a collective identity that becomes the group personality.

         Commitment is the desire of group members to  work together to complete their task to the satisfaction of the entire group.

         Cohesiveness，an extension of commitment, is the attraction that group members feel for each other and their willingness to stick together.

     3. Relevance

Relatedness

Timeliness

Sufficient Length

Clarity

Informativeness

Openness to evaluation

Provocativeness

  4. Being aggressive

•Blocking

•Recognition seeking

•Self-confessing

•Acting the Buffoon

•Dominating

•Help-seeking

•withdrawing