The opportunity that a witness has to view the perpetrator and the level of attention paid have also been shown to affect the reliability of an identification. Attention paid, however, appears to play a more substantial role than other factors like lighting, distance, or duration. For example, when witnesses observe the theft of an item known to be of high value, studies have shown that their higher degree of attention can result in a higher level of identification accuracy (assuming the absence of contravening factors, such as the presence of a weapon, stress, etc.).