The core concept of the journal "Group Decision and Negotiation" is based on the evolving and unified processes of group decision-making and negotiation. These processes are complex and self-organizing, involving multiple parties, various criteria, poorly structured, and dynamically changing issues. The methodologies include: 1. Group Decision and Negotiation Support Systems (GDNSS); 2. Artificial Intelligence and Management Science; 3. Applications of Game Theory, Experiments, and Social Choice; and 4. Cognitive and Behavioral Sciences in Group Decision-Making and Negotiation. Many studies integrate two or more of these areas. The journal provides a platform for publishing theoretical and empirical research, as well as real-world applications and case studies. In defining the field of group decision-making and negotiation, the term "group" is interpreted broadly to include all multi-party contexts, including decision support systems that provide organizational-level support. Group decision-making and negotiation refer to the entire process related to these activities, not just the final choice itself, encompassing aspects such as scanning, communication and information sharing, problem definition and evolution, alternative generation, and social-emotional interactions. Descriptive, normative, and design perspectives are also meaningful in this context. Therefore, "Group Decision and Negotiation" extensively addresses relationships and coordination within group processes. Application areas include internal organizational coordination (such as in operations management, integrated design, production, finance, marketing, and distribution), computer-supported collaborative work, labor negotiations, international organizational negotiations (involving businesses, governments, and non-profit organizations such as joint ventures), international (cross-cultural) negotiations, environmental negotiations, and more. The journal also covers software development related to collective decision-making and negotiation.