The book contains of five chapters. The purpose of chapter 1 is to investigate under which conditions it can be expected that the negotiation partners substitute a competitive definition of the situation for a cooperative one. A general model for negotiation situations has been developed. Several research propositions focusing on the transformation from a win- loose context, to a win-win context are presented. The conditions which the purpose of the chapter focus on, are summarized in a visualized model for negotiation situations. The question to be discussed in chapter 2 is the following: Why are we more inclined to believe in one type of information than another? Recent literature is discussed through a general model of the cognitive authority of information. Inputs into the model are: cognitive processes, cognitive principles, heuristic mechanisms, information processes and characteristics of the speaker (the sender). Outcomes are defined as the cognitive authority of information. Several research propositions based on the model are presented. Chapter 3 Prospect Theory in Negotiations discusses the problem in organizational change projects, that people often resist organizational change. Many change projects in organizations does not reach their goals. The question is why? This chapter investigates how prospect theory can be used to explain people's resistance to organizational change. If we know why people resist organizational change, we as leaders can do something to promote the change project. The objective of this chapter is to advise managers and leaders on ways of reducing resistance to organizational change. We identify seven propositions that explain how managerial strategies reduce organizational change. We recommend seven measures that may be employed by management to obtain support for the negotiated situation. Chapter 4 mastering, discusses the negotiation problem that managers have little insight into issues relating to employees' sense of mastery. The question discussed is how managers can establish workplace conditions conducive to facilitating a sense of mastery for employees, because this will facilitate the negotiation context in the organization. The purpose of the chapter is helping managers gain greater insight into issues relating to employees' sense of mastery in order to contribute to a improved negotiation situation. At the end of the chapter an analytical model consisting of seven elements is visualized, which can be applied as a management tool for negotiation situations. In chapter 5 Attitude change in Negotiations, we discusses the problem related to the difficulty of changing attitudes. The question asked is: How can managers change the attitudes of employees? The purpose is to develop a toolkit that managers can use to change employees' attitudes in negotiation situations. A system of 13 measures that managers can use to change the attitudes of employees is visualized as a toolkit for managers in negotiation situations.