Passage Summary: Since a witness feeling sure doesn't mean they are right, and other people's opinions can change how sure a witness feels, police shouldn't let witnesses influence each other.

Conclusion: Police should ensure that witnesses are kept separate and cannot hear one another during suspect identification lineups.

Reasoning: Research indicates that a witness's level of certainty does not necessarily reflect their accuracy and can be easily influenced by external factors.

Analysis: The argument moves from a factual finding—that confidence is unreliable and easily manipulated—to a practical recommendation for police procedure. The underlying principle must bridge the gap between 'confidence is a poor indicator of truth' and 'we should stop witnesses from influencing each other.' It likely suggests that we should avoid procedures that artificially alter a witness's certainty. Look for an answer that emphasizes protecting the independence of a witness's judgment.