Researchers have also suggested that the manner in which photos or individuals chosen for a lineup are presented can be key to the reliability of an identification. Specifically, lineups should be conducted sequentially, rather than simultaneously. In other words, each member of a given lineup should be presented to a witness by himself, rather than showing a group of photos or individuals to a witness together. According to social scientists, use of this procedure will minimize the effects of the "relative judgment" process discussed above. It encourages witnesses to compare each person individually to his or her independent memory of the perpetrator.