[Sigia-l] CMS and IA

[Peter Van Dijck]

Nuno Lopes wrote:

> I've been reading articles about Faceted Classification, Ontologies,
> Taxonomies, etc etc. Technically speaking and from the engineering point
> of view I come from OOA and Relational Modeling. I have to confess that
> my "ignorance" of the topics that are often talked on this list lead me
> to observe this articles with certain skepticism around their novelty.
> In other words, most of the topics being addressed I see equivalences
> with Relational Modeling and OOA at some point (even between them). With
> leads me to suspect that probably they don't solve much more then what
> we already have mainstream (RDBMS, OODMS, etc) from the point of view of
> engineering.

You are talking about two different things. RDBMS and OODMS are ways of
modelling stuff. Faceted classification systems and ontologies are
models. They can be expressed in an RDBMS or an Object Model. Apples and
oranges.

> findabilitySys - The "Findability" System is responsible for handling
> the creation of multiple strategies aimed to facilitate the search of
> information according using well known multiple organization patterns
> (Indexing, Categorization, Faceting, and others).

Like the name :)

> So my first question is - what are the main differences between
> Relational Models and Ontologies apart from the existence of the notion
> of Classes and Class hierarchies?

Ontologies is just a generic name for
knowledge-base-that-models-knowledge. The actual structure of an
ontology can differ (there is no ONE structure for ontologies. XTM
(topicmaps) provides one example of a defined structure that can be used
to model ontologies. Topicmaps are often kept in a relational database
rather than in the XML format (XTM).

> This leads me to the next question, what is the main difference between
> "Ontology" and an Object Oriented Data Model defined in UML for
> instance?

A specific Ontology structure can be modelled with objects.

> I would like also more information about how to implement a Faceted
> Classification system using RDBMS. 

For a simple hierarchical faceted system, try:
Facet table
- id
- name
Topic table
- id
- name
- parenttopicid
- facetid

As you notice, you could make facets to be topics with no parenttopicid
and just use one table.

> This information could then be exported in some XML dialect to be used
> by indexers or any other system.

How 'bout http://xfml.org

> One other thing that I'm very interested is topic maps and how they
> related with Faceted Classification schemes if there is any relationship
> between them?

Topicmap structure is a lot more complex than a simple hierarchical
faceted classification structure. A hierarchical faceted classification
structure is simply a set of topic trees. To understand topicmaps, check
http://easytopicmaps.com

Hope that helped.
PeterV