The report provides an overview of findings concerning Stated Preference (SP) methods. These are methods which may be used to find the population's willingness to pay for benefits which are not sold directly in markets. We discuss the SP methods of Contingent Valuation, Conjoint Analysis and the Transfer Price method. In many cases the methodological problems common to these SP methods will result in too high an NOK value for the non-market benefits that are valued. Moreover, there will be considerable differences from benefit to benefit as regards how too high the NOK value is. A consequence of this is that non-market benefits that are to be included in the same cost/benefit analysis must be valued concurrently and in relation to one another so that cost/benefit analyses will provide correct ranking of projects.