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Re: [ontolog-forum] Namespaces for ontologies

To: "[ontolog-forum]" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: Duane Nickull <dnickull@xxxxxxxxx>
Date: Thu, 23 Apr 2009 12:31:41 -0700
Message-id: <C616102D.3C0D%dnickull@xxxxxxxxx>
Thank you Pat.  Wise words as always!

Duane


On 4/23/09 10:32 AM, "Patrick Cassidy" <pat@xxxxxxxxx> wrote:

Duane,
  Just on one point:
Ø  [DN] WordNet is where I was also thinking of going but I find it incomplete.  For example, take the definitions of river and creek:
[Rive] 1. a large natural stream of water (larger than a creek); "the river was navigable for 50 miles"
wordnet.princeton.edu/perl/webwn


Ø  [creek] 2. a natural stream of water smaller than a river (and often a tributary of a river)

Circular reasoning or no loose ends?


 
  Actually, there’s nothing wrong with cross-reference, if it proves necessary – it happens a lot at the basic levels.  What it means is that whatever module (context)  holds one concept must also hold the other – they are interdependent (like ‘metric space’ and ‘dimension’ ).  In this case, since there are no objective criteria (e.g. ‘a river must be at least 50 feet across at some point in its length when it is not at flood stage’ or ‘ a river must be at least 3 feet deep for one mile from its mouth’), then that signals that the definitions may be context-dependent (e.g. different locations will have different criteria, different users will use different labels).  Then it may be necessary (depending on the application) at some point to introduce more precise definitions depending on the context, or just refer to the act of affixing a label.  I recall one example of a government study of funding in chemistry departments where the only criterion they could find for whether some part of a university is or is not a ‘Chemistry Department’ was whether the university called it a “Chemistry Department”.  This is not actually circular, because the label affixed and the object itself are not the same thing.
 
But as I suggested, I think that one needs to try as hard as one can to get agreement within some large community to use the same basic ontology, and only give up and look  for alternatives after reasonable efforts have failed.
 
As for WordNet, it is an excellent start, but needs to be formalized, which means reorganized, especially at the top levels.  That might serve as one of the main resources for a tagger’s ontology.
 
Pat
 

Patrick Cassidy
MICRA, Inc.
908-561-3416
cell: 908-565-4053
cassidy@xxxxxxxxx
 

From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Duane Nickull
Sent: Thursday, April 23, 2009 12:40 PM
To: [ontolog-forum]
Subject: Re: [ontolog-forum] Namespaces for ontologies

Pat:

Major thanks for this.  As for the caveat, I had similar thoughts.  What I want to do is a limited roll out and only those who are willing to initially learn the system would be allowed to make the references until it is clear that it works or not.  This probably sounds very elitist but that is how I want to proceed.

The time issue is also something I have thought about however the goal is to put the theory into practice and see if it is or is not useful.   As with complexity, I would assume that the real world results will speak for themselves.

Wordnet is where I was also thinking of going but I find it incomplete.  For example, take the definitions of river and creek:

1. a large natural stream of water (larger than a creek); "the river was navigable for 50 miles"
wordnet.princeton.edu/perl/webwn

2. a natural stream of water smaller than a river (and often a tributary of a river)

Circular reasoning or no loose ends?

I guess I am curious to see this ported to the masses to see where it fails or works.

Duane

On 4/22/09 5:45 PM, "Patrick Cassidy" <pat@xxxxxxxxx> wrote:
Duane –
  I don’t have any suggestions about how one might best use URL’s to reference ontology elements.  However, I do have some thought about whether one might or might not want to.
 
  I’m not quite sure what you intend to accomplish by allowing taggers to link their tags to upper ontology elements from any old ontology.  Since the relationships of the upper ontologies to each other have not yet been well developed, it would only be useful for those who have chosen to tag by reference to the same ontology.  That might be somewhat useful, but see the caveat below.
 
If, however,  you think this is a way to bring the power of crowds to actually finding the relations among ontologies (i.e. a tag referenced to more than one ontology creates a putative identity link), then this is an interesting new way to go about the ontology mapping task.  But that method has a problem:
Caveat: since upper ontologies are hard to understand, I suspect few taggers will have the patience to work though those structures except to find the most common tags like “person” or “organization”, and in those cases the bare tag would probably have a common-sense meaning which others would understand without the ontology reference.  
 
An example of the problem is the axiom you gave, apparently taken from SUMO.  To interpret it, one needs to read the documentation for the ‘time’ relation.   For perspicuity, I would recommend that any project of that type at least rename the relations with a verbal form – in this case ‘existedAtTime’.  That can help users at least avoid having to puzzle over their recollection of the meaning and polarity of the relation.  The whole relation means that an Object exists at every time point within *some* time interval. I have never been able to figure out under what circumstances this axiom might be useful in inference, though it makes a sensible philosophical statement about physical objects.
 
It would be good to see crowds adopt a single ontology that is well-structured but easy to understand.  In that case I think the best tactic is to have such an ontology developed by the taggers themselves for their purpose, with the help of some willing ontologists.  The existing ontologies can be taken as starting points, but having the taggers use a common ontology would be a lot more effective.
 
If you think that there is a clamor among taggers to use some particular existing ontology, so that that one of them must be included in the mix that the taggers use, I would be very interested to know which ones have that distinction.  So far the biggest public tagging corpora I know of reference WordNet.
 
   As for versioning, in the cases I am familiar with, new elements tend to get added, but the basic structure of the main elements seldom changes (though the WordNet indexes change).  There are occasional exceptions, one of which happened with the way Cyc handles attributes, a few years ago.    But since the process you describe is so subject to variation that I think that the variation added by ontology versions will not be significant, and I wouldn’t worry about versioning – at least beyond the 1.0 stage.
 
Pat   
 

Patrick Cassidy
MICRA, Inc.
908-561-3416
cell: 908-565-4053
cassidy@xxxxxxxxx
 

From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Duane Nickull
Sent: Wednesday, April 22, 2009 6:10 PM
To: [ontolog-forum]
Subject: [ontolog-forum] Namespaces for ontologies

Hey all:

I am right now placing FOL binary relationships into the associations binding for labeled relations in a test Registry-Repository.  I am doing this because I got sick of just talking about this and not actually coding and doing something to solve the problem so the Canadian cowboy instinct to code first and see where problems arise has taken over.  

I have run into a problem that I would appreciate input on. My goal is to bind something like this:

(=>
      (instance ?OBJ Object)
      (exists
            (?TIME1 ?TIME2)
            (and
                  (instance ?TIME1 TimePoint)
                  (instance ?TIME2 TimePoint)
                  (before ?TIME1 ?TIME2)
                  (forall
                        (?TIME)
                        (=>
                              (and
                                    (beforeOrEqual ?TIME1 ?TIME)
                                    (beforeOrEqual ?TIME ?TIME2))
                              (time ?OBJ ?TIME))))))

..to a registry-repository instance to allow folksonomy tags to reference the upper level ontology classes the folksonomy tag owners believe they belong to.  Additionally, each instance of a folksonomy tag may have * relationships to other ontology classes or even other folksonomy tags.  The latter relastionships can be defined in terms of contrained relationship tags like “synonym, disjoint, etc.”.

I want to represent all upper ontologies however some of them contain subtle nuances between their terms.  Dolce, SUMO and others have defined binary relationships like transitive, intransitive, reflexive, irreflexive, symmetrical as well as some partial ontologies.  The problem is that there are no namespace qualifications for these so I want to introduce that into my work.  I was planning on just using the root URL’s for each work however there are versions possible in some of the work.

I would like this to be in the firm of  <upper_ontology_identifier>+<version_or_instance>+<uuid> as a classifier followed by the term label such as “transitive”.  I will probably use URI’s for the UUID.

Question:

Has anyone ever come across a similar problem and if so, how did they solve it?

Thoughts and comments welcome too.

Duane



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