Reference ratings are used to provide a measurement aid with custom reference alternatives when specifying ratings. Reference ratings are represented by a icon and exist globally in a model under the top level reference-rating folder
in the navigation pane.
When editing ratings, reference ratings can be selected and superimposed over the open ruler to provide a guide for rating alternatives.
Reference ratings are created and modified in the same manner as normal ratings, except that they are populated with a separate set of Reference Alternatives that are excluded from computations of overall scores.
In Tetra GDM reference ratings can only be created by the model owner. However, all decision makers can view and use the model's reference ratings.