b.Interdependence, Common Goal, Group Personality, Commitment, Cohesiveness, Group Conflict, Social Facilitation, Gender Differences, Group Size, Norms.
Relevance：Members’ comments should pertain to the topic and goals of the discussion at hand and should deviate only when tension needs to be released.
Relatedness：The goal of relatedness is to make sure that contributions tie in with what has been said before and what is apt to be said next.
Timeliness：To give more impact to a good idea you should, introduce it at a favorable time so that it gets the group’s full attention and consideration.
Sufficient Length：Choosing the best length for a comment requires good judgment. The goal is to make sure that the comment you contribute is long enough to make your point.
Clarity：Always remember that meanings are in people, not in words. Thus, you cannot assume that everyone in the group will understand your idea in the same way that you do.To avoid misunderstandings, define your terms and provide examples to ensure a common ground.
Informativeness：Make sure that your statement are accurate and objective. This requires having a good understanding of the topic and doing prior research. Cite source of information when appropriate, and select sources that are not biased.
Openness to evaluation：Group discussion can lead to the best possible information and the best possible decision, but this will happen only if members open their comments to evaluation. Criticism should not be ignored or avoided. At the same time, members must remember that evaluation can be constructive only when they focus on the contribution and not on the person.
Provocativeness：Comments should be made not only to bring the group closer to its goal, but also to fuel thought for further contributions. Lack of time should never be the sole reason for closing off discussion if an idea has not been fully discussed and evaluated.Asking questions, challenging ideas, and disagreeing can be valuable contributions as long as their goal is to make the final group product the best one possible.