Read over the rubric carefully before the group activity begins. These rubrics generally grade each individual on how he performs within the group. For example; does the person benefit the group as a whole? Another element of a group activity rubric is the outcome created by the group, regardless of individual performance. Familiarize yourself with the goals of the assignment and your expected outcome. The rubric should include specific descriptions of the expected performance level, so scoring the rubric is easier. For example; a description of a strong performance is "The team successfully accomplished the team building activity and worked as a cohesive whole." An example of a weak performance description is "The team only partially finished the activity and tended to work as individuals."
Observe individuals and the group according to the rubric you laid out. Ask yourself, is the team working together on their assignment? Is each individual participating? Did they complete the activity as I described it? Is each individual contributing her best work? Reread the descriptions to ground yourself in your own rubric goals.
Score the rubrics using a consistent method. For example; many rubrics use a four-point system, with one being the weakest performance and four being the strongest. Your rubric should include areas for individual and group performance scoring. Each rubric should have multiple areas to assess, such as overall performance, clarity or strength of the work, and if there was any strong leadership. Respond to the questions you asked on the initial rubric aid and score accordingly.
Convert your rubric to another scoring system if necessary. For example; you may have used the four-point system, but need to give letter grades out to each of the teams. Generally, a score of one equals a low "C" or a high "D" letter grade. A score of two equals a low "B" grade, and scores of three and four equate to a high "B" or high "A" grade.