classical utility theory and its fuzzy counterparts, exact and heuristic optimization method and modern mul- criteria decision support tools such as AHP or ELECTRE. Possibilities of analyzing and dealing with uncertainty are also brie y presented. The use of each method is illustrated with examples. In addition to decision aid methods, we present the basic theory of participatory planning. Both hard and soft methods suitable for partici- tory or group decision analysis are presented, such as problem structuring method and voting. The criticism towards decision theory is also covered. Finally, some real-life examples of the methods are presented. Annika Kangas Department of Forest Resource Management University of Helsinki Jyrki Kangas Metsahallitus ¿ Mikko Kurttila University of Joensuu v Acknowledgements Manyresearchersandstudentshavehelpedusbyreviewingchapters,suggesting- provements and even checking our example calculations. We would like to ackno- edgethesereviewers, Ms. AnuHankala, M.Sc. TeppoHujala, M.Sc. AnnuKaila, Dr.