The data model is usually exposed by the application, but it is also possible to define additional objects within KUIML.
Model element can be parameters (literals), strings (text), curves (y=f(x)), surfaces (z=f(x,y)) and custom properties (custom data). All data model elements fall into one of these categories. These elements handle the data inside the model, whereas behavior is described using actions (ACTION) or Model Links.
As part of the data model, Metadata can also be defined for most elements or their attributes.