Interesting discussion!
On 25/6/09 14:15, Simon Reinhardt wrote:
Hi
Bernhard Schandl wrote:
[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>
I like this. The former has several problems anyway: you have to repeat
properties if they can hold between several classes [3] and you have to
draw lines connecting lines for expressing sub-properties or inverse
properties [4] which looks rather confusing and is not supported by many
visual modelling tools.
Yeah, my [4] is at my threshold of tolerance for chaos in a diagram. I
wanted a way to show the core of the FOAF spec in a picture, so tried
(despite similar concerns to those mentioned in this thread) the style
of putting domain/range directly in an instance-like style.
In http://www.flickr.com/photos/danbri/1856478164/ ([4]) I try to do too
many things at once:
* show the classes that each property is used with
* show sub-property relationships
* show sub-class relationships
* show some typical properties
* show attachment points for "friends of FOAF" namespaces (DOAP, SIOC,
DC, Geo etc), with classes and with sample properties
This is a lot of information.
I did try to make a "gradual reveal" slideshow version, building up from
something simple. It wasn't great. The layout was done by hand to
minimise crossovers, and looking at it, I think the whole structure
could be twisted/stretched to be more evenly presented. It was fiddly to
do though.
A sample of instance-data would probably convey most of the same
information about domain/range, and would allow subclasses reasonably
too. Sub-property would remain hard...
If anyone wants to mess around with the FOAF example, source data in
OmniGraffle format is here and also in SVG: just do "svn co
http://svn.foaf-project.org/foaf/trunk/xmlns.com/htdocs/foaf/spec/images/";
[3] also shows a combination of the two
problems: if you draw several lines for one property, you have to
connect sub-properties to each of them or to an arbitrarily selected
one. The only downside I see here is that adding ellipses for properties
makes the diagram a bit more bloated.
I don't find [3] very readable. There was another Harmony ABC diagram (I
think from Carl Lagoze) in
http://www.ilrt.bris.ac.uk/discovery/harmony/docs/abc/abc_draft.html#Simple%20Rules
that uses dotted lines for implied types, I think this can work well in
instance level presentations.
cheers,
Dan
Regards,
Simon
[3] http://metadata.net/harmony/ABC_Class_Hierarchy_with_Properties.gif
[4] http://www.flickr.com/photos/danbri/1856478164/ (sorry Dan!)
