Crisis negotiation was initially introduced as hostage negotiation in the early 1970s. It is different from the common forms of negotiation, which assume that all participants wish to bargain, are happy to do so, and happy to exchange proposals as part of the problem-solving process. Part of the role of crisis negotiation is to make efforts to change the situation from that of crisis to a more normative problem-solving process. Crisis negotiation attempts to do this in a number of ways, such as creating a climate where compromise and problem solving can be considered by the individual in crisis, as well as using a range of crisis negotiation strategies. When exploring mental illness and personality disorder, one of the few authors who have considered the application of crisis negotiation strategies to such individuals is Strentz. One of the main challenges in the crisis negotiation literature is that of effective evaluation.