Group communication involves interacting and influencing each other to accomplish common goals. Effective groups have clearly defined, consistent, and acceptable goals. The optimal size is smallest to do the job, and members bring diverse but relevant skills. Cohesiveness and productive norms like ground rules help the group achieve synergy and outcomes greater than individuals. Forming, storming, norming, performing, and adjourning describe the stages of group development. Analyzing problems, determining criteria, identifying solutions, and evaluating alternatives against criteria leads to a decision using methods like consensus or majority rule.