The discussion emphasizes that an effective witness cooperates fully with authorities, takes part actively in the entire judicial process, and testifies honestly and fairly at all hearings. It also notes that prosecutors are unable to convict many criminals without the help of cooperative witnesses. It explains the roles of various courtroom personnel and urges witnesses to be courteous, review their statements before testifying, stay calm, answer questions directly, make certain they understand the questions and ask for a break if needed. List of sources of additional information and help.