Criteria of expressiveness of the data

Variations that should be used for designing expressive graphs and satisfying the users information needs, should at least consider the following data characteristics (Roth and Mattis, 1998b):

Relationships within hierarchies: important rule

Often the attributes linked to the dimensions in a hierarchy are closely related to each other and are often attributes of the same entity. A customer dimension is related to the region dimension that in turn is related to the country dimension and this can be a reason to make a hierarchy in order to reduce the amount of categories of the dimensions. Dimensions of higher order (those dimensions that have the lowest amount of categories) should reside higher in the hierarchy. The product-line dimension is of a higher order then the product dimension and therefore the hierarchy is as follows: Product-line à Product.