La necesidad de considerar el valor de bienes sin mercado en distintos contextos, ha llevado al uso de metodos de valoracion basados en preferencias. Estos metodos, a pesar del aporte de informacion que proporcionan, adolecen de ciertas dificultades reconocidas en la literatura economica, entre ellas, los problemas sobre informacion relevante a proporcionar, sobre formacion de preferencias para bienes ambientales y sobre la obtencion de valores comunitarios frente a individuales. Para salvar las criticas, se ha recurrido al uso de tecnicas de participacion en conjuncion con un metodo de valoracion, en general la valoracion contingente. En este trabajo se combina una tecnica de participacion conocida como jurados de utilizadas con exito en distintos contextos por separado. Aqui las aplicamos para evaluar las mejoras promovidas por la Directiva Marco del Agua, la mayor reforma legislatica en materia de aguas en la Union Europea. Esta aplicacion muestra que los jurados permiten aplicar los experomentos de eleccion con exito, obteniendo una mas correcta revelacion de las preferencias indiciduales y colectivas, preferencias que, en nuestro caso y para los atributos seleccionados, practicamente coinciden...The need of information and some quantification of environmental values in money terms is often demanded for the decision making process increasing the use of valuation methods based on preferences. This increase has highlighted the critics on stated preference approaches to environmental valuation, where criticisms have focused on problems of information provision, the notion that people have pre-formed, certain preferences for environmental goods, and notions of community rather than individual values. To save the critics has led to some researchers trying to incorporate elements of participatory approaches in a modified form on contingent valuation. In this paper, we attempt a combination of of the participatory technique known as the "citizens' jury" with choice modeling, a stated preference technique increasingly favored by environmental economists. Our application is conducted in the context of water quality improvements under the Water framework Directive, the most significant reform in water legislation in the European Union for many years. We find that the choice experiment format can be successfully implemented in a "jury" format, but that moving from individual to collective choice produces, in this instance, a rather small change in both values and preferences, in other words, moving from individual to citizen values, estimates of the river attributes selected, do not change significantly between the two contexts.