Organize groups. Divide the participants into groups of 1 to 4 people.
Distribute the unfinished story. Give each group a copy of the story. You may use different versions of the story with different groups.
Brief the participants. Explain that the story contains some missing elements. Ask the members of each group to find suitable information from the reference manual to complete the story. Emphasize that there are no wrong answers, but some answers are not as right as others. Ask the groups to note down page references.
Announce a time limit. 15 minutes should be sufficient most of the time. Some groups may finish earlier, but that should not present a problem.
Conclude the session. Call time at the end of the 15 minutes. Convene the groups back into the overall group. Ask each group to read their completed story. At the end of the presentation, conduct a poll to decide which story is the best one.
Source: Thiagi Group - Gary Rush