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3389RE: [TaxoCoP] data modeling and taxonomy

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  • Bob Bater
    Jan 16, 2010
    • 0 Attachment

      Matt et al.,

       

      Sorry for the long delay in responding, I’ve been tied-up with other things. I’m not intending to restart this thread, but simply to be polite in responding to Matt’s question below.

       

      I guess my use of the word ‘ontology’ is what Wikipedia describes under the article Ontology (Information Science):

       

      Ø  In computer science and information science, an ontology is a formal representation of a set of concepts within a domain and the relationships between those concepts. <

       

      In my case, the ‘domain’ is an activity system – usually an organization or part of an organization. At that point, I disagree with the Wikipedia entry where it says:

       

      Ø  An ontology provides a shared vocabulary, which can be used to model a domain. <

       

      I don’t believe ontologies generate vocabularies directly. They provide a shared depiction of concepts and their relationships in an activity system, and it’s only in the next stage (the taxonomic system) that terms are agreed for describing those concepts. A third stage – the retrieval system – is where one recognizes that different communities use different terms for the same thing, and if people are to retrieve information using their own terms, then these must be reconciled through the conventional techniques of preferred and non-preferred terms and related terms exemplified by the thesaurus.

       

      In this sense, my ‘ontology’ is analogous to what Wikipedia describes as ‘Upper ontology (information science)’. I don’t use the ontology itself to make inferences, but to draw the broad outlines of my taxonomic system, which is where I start making inferences to construct the hierarchical and referential relationships.

       

      I don’t know if it will make my approach to and use of ontologies any clearer, but anyone interested can look at a presentation I gave to the NKOS workshop in Vienna in 2005: http://www2.db.dk/nkos2005/Bob Bater.pdf.  

       

      Best regards,

       

      Bob

       

      From: TaxoCoP@yahoogroups.com [mailto:TaxoCoP@yahoogroups.com] On Behalf Of Matt Moore
      Sent: 06 January 2010 01:01
      To: TaxoCoP@yahoogroups.com
      Subject: Re: [TaxoCoP] data modeling and taxonomy

       

       

      Bob,

      "My 'working hypothesis' in this respect does not include the need for ontologies to enable the making of inferences."

      I think you're using a particular version of the term "ontology" that might cause a little confusion. How does your ontology differ from a faceted classification structure? My understanding of ontologies is that they specify the "verbs" that link "nouns" as well as the nouns themselves (so they specify what a certain subclass of person can do to a certain subclass of document for example). What's "in" and what's "out" of your model?

      Cheers,

      Matt

       


      From: Bob Bater <bbater@...>
      To: TaxoCoP@yahoogroups.com
      Sent: Wed, January 6, 2010 10:30:02 AM
      Subject: RE: [TaxoCoP] data modeling and taxonomy

       

      Heather, Gabriel, John, Keith & anyone else who's following this thread:

       

      I'm still feeling my way around these kinds of issues (have been for years), and have no hard-and-fast solutions. However, I do have some 'working hypotheses' which I find to be helpful. I'll refer to them as I respond to a few points made by John, Keith and Gabriel.

       

      Firstly, John is quite right in pointing out that both data models and taxonomies are necessarily bounded. Who'd want to undertake a data model or a taxonomy of *everything* ? Well, I suppose Melville Dewey, UDC, LCC have all attempted it, with varying degrees of success. But that's a topic for another day. In an organizational context, both data models and taxonomies need to be restricted to a specific domain, if only for practical reasons.

       

      John also says:

      > For example, if all of the 'entities' that a data modeller wanted to use were already classified by a taxonomist and resided in a master data management inventory, then a sort of symbiotic relationship could exist between the necessarily narrow application of the data and the universal 'connectivity' of a fully faceted business vocabulary. <

      I see this as the role of the 'over-arching ontology which expresses the context of both data model and taxonomy', to quote my own post. The ontology, developed first, ensures that both data modeller and taxonomist are singing from the same hymn sheet. That will also prove of great benefit to data warehouse developers, document managers, records managers and information architects, further down the line.

       

      Keith says that he finds taxonomies are regarded as:

      > "THE solution" rather than being viewed as "A solution" or part of a larger system of models and decision-making depending on the nature of the enterprise <

      Taxonomies have been over-egged. Many in the field think 'taxonomy' first and context later. IMHO bad! Build the ontology first, then do your data modelling. Then you'll have done a PoC (Proof of Concept) for the domain - identifying the entities which are important, their important attributes (for the data modellers) and a first lead-in to the language people use to refer to them (for the taxonomists) . Using both the ontology and the data model, define the key attributes which different communities regard as important to them when they want to access and process information. That gives you a metadata application profile for each community which can be aggregated into a corporate metadata profile. Only then do you look at each attribute in each profile and decide how it is to be populated. Sometimes, it will be an /ad hoc/ value; sometimes the value will be drawn from a fixed, flat list; sometimes the value will be drawn from an organized, maintained hierarchy of values - a taxonomy. For me, the metadata profile comes first. A taxonomy only becomes relevant if a metadata element requires it.

       

      Gabriel said:

      > (I said  "ontology / taxonomy" in the above because I'm not clear myself whether our CM does satisfy a full definition of "ontology"; for example as yet we have no mechanisms for making inferences). <

       

      My 'working hypothesis' in this respect does not include the need for ontologies to enable the making of inferences. That is a requirement of strict 'ontologies' in the Semantic Web sense. For me, ontologies provide the context for ensuring that information and knowledge management structures and systems are coherent and interoperable.

       

      Keith said:

      > Getting at just where taxonomy, data modeling, and ontology specification begin, end, and overlap is really welcome.  <

       

      Again, my 'working hypothesis' is that ontologies come first, specifying the entities involved in an activity system, and their relationships. Data modellers will want to define the attributes of each entity and to characterize their relationships more rigorously, to enable their capture in the highly structured world of the DBMS, focused on logical consistency.

       

      Information managers, on the other hand, are less data-focused and more user-focused, concerned with linking entities and their key attributes to the concepts - and the terms which represent those concepts - employed by workers. So - where appropriate - they build a taxonomy proposing terms to be used for those concepts, reflecting the taxonomic relationships inherent in any domain - generic, partitive, instantial. While the taxonomy can establish the entities (concepts) involved, and their relationships, it cannot dictate the terms which people use to refer to those concepts. Provision is made therefore for variance in terminology by developing a thesaurus, which allows people to search using their native term, and for back-end software to translate this into the 'preferred term' established by the taxonomy.

       

      Hope that stimulates some thoughts. Meanwhile, where's Patrick Lambe in this thread? Patrick, I'm sure you have some informative views on these issues. Please join us.

       

      Regards,

       

      Bob

       

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