A.   A number of people united by the same target, using the knowledge or skills of each member, working together to solve problems to achieve the ultimate goal.

B.   Interdependence, common goal, group personality, commitment, cohesiveness, group conflict, social facilitation, gender differences, group size, norms.

C.   Relevance、Relatedness、Timeliness、Sufficient Length、Clarity、Informativeness、Openness to evaluation、Provocativeness.