- From: Wafik Farag <Wafik@Farag.net>
- Date: Fri, 30 Sep 2005 15:56:25 -0400
- To: <wangxiao@musc.edu>, <public-semweb-lifesci@w3.org>
Hi Wangxiao,
>> 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.
Neither do I. But for the sake of labeling things, it was refered to it as
an "over-arching layer"
> It is just a visual clue I
> guess.
Fine you can call it visual clue. The important part is how will this clue
or layer ("over-arching") connect two ontologies that change!!!!!!!!
>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.
Great maybe you are right -- if 2 is wrong this means that the over-arching
layer must change when the underlying ontologies change -- is this what is
said?? I am just trying to get some consenses that we are all talking about
the same thing -:) I hope we don't do like other projects where each group
work on an ontology and at the end we find that we still can't connect those
ontologies -- a.k.a. same like relational model. At least the relational
model was clear that each schema doesn't integerate.
> 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.
Correct, the point is what is meaningful for one might not be for another
... as Eric said the connection needs to be task independant. Now if one
wants to update one ontology what will happen to the connection that is
linking it to the other ontology ...
>
>> >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.
Yes, agreed the ontology must be consistent -- but how??
Anyway, this needs a commitee or a grant to be solved and not an email blog
>
>
>
Received on Friday, 30 September 2005 19:56:35 UTC