Often the benefit of user interfaces is in simplicity. For example, in one DSS used for supplier selection, users are required only to enter information into a limited number of cells in a matrix. To them, this provides complete flexibility because they can still get decision support even in the face of incomplete information. Once the data entry are complete, the DSS ranks the criteria by importance and presents a model that displays only those factors that ranked highly. This facilitates comparison of alternatives among important dimensions. In addition, if a decision maker notices the absence of a particular criterion that he or she believes is important, he or she is warned of a problem immediately.