The important issue of how to overcome rigidness, inadequacy and human inconsistency regarding conventional assumptions on preferences in decision making (for example, regarding yes/no crispness or transitivity) is discussed by well-known experts in this volume. In the introductory articles, analyses of those conventional assumptions are given and the need for reconsiderations and changes as to preference-related aspects is advocated. The following contributions are mainly concerned with issues related to valued (including fuzzy) preference relations, such as analysis of their properties and their use in various decision making and choice problems and in group decision making.