Final answer:
Groupthink can be prevented by encouraging dissent within the group, seeking outside opinions, voting in private, withholding position statements from the leader, conducting research on all viewpoints, and developing a contingency plan.
Step-by-step explanation:
Groupthink can be prevented by encouraging dissent within the group, seeking outside opinions, voting in private, withholding position statements from the leader until all members have voiced their views, conducting research on all viewpoints, and developing a contingency plan. These strategies help to avoid the negative effects of groupthink, such as faulty decision-making and the quashing of dissenting opinions.