While physical evidence provides the most accurate information, verbal information, if carefully evaluated, is also valuable. Interviews at the collision scene give those involved an equal opportunity to present their perceptions of what occurred and provide information that identifies avenues to be explored during the investigation. Because perceptions are influenced by background, biases, and other factors, officers should be trained to minimize and assess these influences during the interview. Officers also must realize that perceptions of what happened will be selective because of driver inattention and a desire to avoid blame. During the identification stage of the interview, questioning establishes the identity of each driver, determines the physical condition of the drivers (e.g., injury, intoxication, sleepiness), establishes vehicle ownership, and determines direction of travel prior to the collision. The information phase of the interview is supposed to elicit narrative versions of what happened. The interview during this phase should be private, and the officer should avoid interruptions, verify information, and focus attention on what is being said. Interviews with passengers can help in confirming what was learned from the drivers. The remainder of the investigation should test the reliability of statements, fill in gaps, and answer any remaining questions.