We review some experiences with multicriteria decision suppport systems (MCDSSs). We show that MCDSSs have been able to deal only with to the 'choice' phase of decision rather than with tasks involved in developing criteria and alternatives. This strongly limits the use of MCDSSs within organizations. Designers should focus their efforts on alternatives. This weakness of MCDSSs in dealing with alternatives can be allievated by emphasizing the cooperation between the decision maker and the system. We stress the interest of modeling cooperation, explanation and context to improve MCDSSs acceptance. Beyond MCDSSs some organizational lessons extend to other DSSs.