Visualization of domain and range

Hi,

a couple of times now I ran into misunderstandings by students  
regarding a common visualization style of property domain/range  
relationships in ontologies. Actually, it is quite common to draw  
diagrams of ontologies in a style similar to ER diagrams, where  
classes are represented as ellipses, and properties that have these  
classes as domain/range are represented as arcs between these ellipses  
(e.g. [1], which is meant to describe the domain and range for  
foaf:holdsAccount).

However many "newbies" to RDF and ontologies are confused by this,  
because the triple

foaf:Agent foaf:holdsAccount foaf:OnlineAccount .

is actually not contained in the ontology. It's hard to explain them  
the difference between this way of representing ontologies and the  
graphical representation of the actual triples. Thus I ask everyone to  
reconsider the way you visualize ontologies in publications,  
tutorials, etc. to make them consistent with the "normal" way of  
graphical RDF notation.

[1] <http://www.ifs.univie.ac.at/schandl/2009/06/domain+range_bad.png>
[2] <http://www.ifs.univie.ac.at/schandl/2009/06/domain 
+range_better.png>

Best,
Bernhard