RE: Antwort: RE: Semantic web article in Nature Biotechnology

- Wafik 

> This means that in SW the following statements are correct?:
> 1. SW connects ontologies through an over-arching layer 2. 
> The over-arching layers do not change with the change of the 
> underlying ontologies.
> 3. Several layers of over-arching layers could exist for 
> aggregating sets of ontologies.
> 4. An over-arching layer does not contain any details about 
> the sub-domain ontologies it is aggregating.
> 5. A DAG (Directed Acyclic Graph) is used to connect 
> ontolgies in the over-arching layer.

I don't know what this over-arching thing is.  It is just a visual clue I
guess.  A RDF is a flat DLG.  Any layer is arbiturary because you have to
define what you mean by higher layer? Is it a rdfs:subClassOf or is it
rdfs:type? So, 2 is certainly wrong.  The "connection" if you meant an
binary property in this case, definitely change the semantics and it also
depends on what the "connection" is because it may create inconsistency.
 
> For example, if I have one ontology has protein structures 
> and another ontology has protein activity.  After the 
> over-arching layer connects both ontologies will one be able 
> to ask the simple question: "which structure belongs to which 
> activity"?.

Of course, if you "connect" them in a meaningful way to you.

> >From what I am finding from the other emails -- so maybe it 
> is not only
> me -- that it is not clear how the over-arching layer that 
> contains no detail information and is not affected by changes 
> in the underlying ontologies and can still answer the 
> questions that allow us to navigate across ontology 
> boundaries without knowing the other ontology layout.  I am 
> assuming that the goal of the over-arching ontology is 
> creating the link between ontologies allowing to share.  i.e. 
> biologist and chemist can connect.

An ontology demands consistency.  Two "linked" ontology will become one
ontology and must be consistent to be useful.  Again, "principle of
orthogonal domain" as I call it is one of the important aspect to consider
during ontology creation.

Received on Friday, 30 September 2005 03:07:12 UTC