varying degrees by empirical research. Timothy Hart and Ternace Miethe used data from the National Crime Victimization Survey (NCVS) and found that a bystander was present in 65 percent of the violent victimizations in the data. Their presence was most common in cases of physical assaults (68%), which accounted for the majority of these violent victimizations and less likely in robberies (49%) and sexual assaults (28%). The actions of bystanders were most frequently judged by victims as "neither helping nor hurting" (48%), followed by "helping" (37%), "hurting" (10%), and "both helping and hurting" (3%). Half of the attacks in which a bystander was present occurred in the evening, where the victim and bystander were strangers. Ambiguity and consequences Ambiguity is one factor that affects whether or not a person assists another in need. In some cases of high ambiguity, it can take a person or group up to five times as long before taking action than in cases of low ambiguity. In these cases, bystanders determine their own safety before proceeding. Bystanders are more likely to intervene in low ambiguity, insignificant consequence situations than in high ambiguity, significant consequence situations. Latané and Rodin (1969) suggested that in ambiguous situations, bystanders may look to one another for guidance, and misinterpret others' lack of initial response as a lack of concern. This causes each bystander to decide that the situation is not serious. Understanding of environment Whether or not a bystander intervenes may have to do with their familiarity of the environment where the emergency occurs. If the bystander is familiar with the environment, they are more likely to know where to get help, where the exits are, etc. Bystanders who are in an environment in which they are not familiar with the surroundings are less likely to give help in an emergency situation. Priming the bystander effect Research done by Garcia et al. (2002) indicate that priming a social context may inhibit helping behavior. Imagining being around one other person or being around a group of people can affect a person's willingness to help. Cohesiveness and group membership Group cohesiveness is another variable that can affect the helping behaviour of a bystander. As defined by Rutkowski et al., cohesiveness refers to an established relationship (friends, acquaintances) between two or more people. Experiments have been done to test the performance of bystanders when they are in groups with people they have been