A couple of things I've been about lately

I've been silent here for over two months now, my blogging time devoted to the Mondeca blog in French Leçons de Choses. But there is a couple of things I've been working on, worth mentioning.

I've exchanged with Michel Biezunski on his Data Projection Model , and found out that its genericity and simplicity made it easy and straightforward to express the structure of Mondeca ITM, without the borderline hacking needed when using either OWL-RDF or XTM for the same task. Now open questions: What will happen with that model? Who will see the benefits over languages already in this space, and singularly over RDF? Who will build tools supporting it?

Been wondering if a semiotic approach could shed some light on our thoughts on referents, and came out with a RDF semiotic triangle. The URI is the signifier, the RDF description is the formalisation of the signified concept associated with the URI. The referent is out of the language and signs realm, and should stay there. In this approach, attempting to achieve a representation of the referent, even using tricks as blank resources or hubjects of any kind, is therefore a recursive trap and actually a non-sense. So any declaration of same-ness or identity of referents should be avoided. Only concepts bear identity, not their referents. From that point on, came to the idea that linking different concepts/signs (URI + RDF description) which humans consider to have more or less similar referent will take the form of processing rules, more than declarative semantics.

Thanks to Jakob Voss for this post in a long thread on public-esw-thes list, which really triggered a kind of illumination about this. As an example, trying to say that my SKOS concept a:Restaurant has the same referent as your OWL class b:Restaurant through any RDF declarative relation between those two resources shoud be avoided. But I can set in my system a functional rule expressing that any document of which subject is an instance of your b:Restaurant class will be indexed against my a:Restaurant concept. The referent is represented nowhere, but it is acting at the core of this rule.

Actually we have this very indexing rule mechanism working in some Mondeca applications, and I have submitted a paper to XTech 2007 about it. More to come if ever the paper is selected.

Lately, got interested again in triggering some process to have languages available not only as tags to use in XML, but as proper RDF resources. This is an old story tracking back to OASIS Published Subjects Technical Committees, and singularly PSI for languages. Track this topic on ESW Wiki, and see here for ongoing thread and more explanations. There again, my proposal is to forget absolute identification of a language by a URI. Concepts identified by URI are the properties and property values than can be declared for a language, and let applications decide on which properties are useful to them. No absolute rule saying that two descriptions refer to the same language.

Leçons de Choses

My blog activity lately has been dedicated to launch the new Mondeca Blog - yes it's in French. Sorry about that.

Geonames enters the Semantic Web

I'm quite happy of this. The collaboration with Marc at geonames started as a simple deal : provide the ontology, said he, and I'll provide the Web Service. So did I, and so did he. This is a fantastic Web 2.0 place to play in. It already had Web Services and wiki using Google Maps, and now he has the SW interface ...

Back to Earth

I've been quite silent here lately. Put more focus on actually working stuff than theoretical musing, and singularly on various geo-unameit technologies such as geocoding, geotagging, geo microformat, and the collaborative databases using them like geonames, wikimapia ...
Places are the most fascinating use cases when it comes to identification and description, and all those technologies and their ability to interface with each other tend to prove that information about some place can be aggregated without any consensus or explicit declaration of what this place (or a place, in general) actually is, but by providing hubs between data, and interfaces putting together data somehow relevant to this place (such as Google Earth, Google Maps API and the like). Geonames web services provide a good example of this.

In defence of 404

Following the announce on the Semantic Web list of the publication of RDF geographical codes by french INSEE, a lively debate with Dan Connolly about access vs description.

More thoughts on that Blue Glass

John Black commented on my previous post, providing links to interesting pieces of thoughts. Anatomy of a Reference and Ambiguity and Identity are certainly in the line of what we try to entangle here.

Let's put those pieces together. John's blue glass, physically tagged with its URI is a clear example of the difference between access and naming as explained by Pat Hayes. What is accessed using this http URI is an image of the blue glass, but the URI is intended to name the glass itself. Tagging physically the blue glass with a URI sticker or a bar code is something very close to what Pat calls ostention, but it's not the silver bullet to kill ambiguity.

As John clearly points, when you stick a tag somewhere in the physical world, you still need interpretation to know which part of the world is tagged this way, since the world is not "naturally" divided, things and their limits are always the result of some mental operation of division. So a common interpretation of the tag needs a common understanding of the limits of things, and having a common understanding of classes of things, and which kind of tags you put on which class of things is really useful. This is something well known in geographical maps. On ill-designed maps, names are not printed properly, and it's often unclear what (town, river, mountain ...) is named. In well-designed maps, there are a lot of implicit or explicit disambiguation tricks, such as fonts, colors, position of the name vs the named feature etc. One has to know all that to make sense of the map (actually many people are not able to make sense of a map properly). When you come to the ground, you have similar physical tags indicating towns, rivers, streets and house numbers, and you also need similar knowledge to construe those tags in context : this kind of sticker is for a town, that kind is for a street, and so on. And even so, what is the limit of a town, a street, a valley or a mountain remains basically undecidable.

[2016-06-20] John Black's Kashori archives have moved. The reference articles are now here:
http://www.kashori.com/archives/2006_06_11_archive.html
http://www.kashori.com/archives/2006_07_02_archive.html

Ambiguity, Ostention and Description

Pat Hayes' In Defence of Ambiguity, presented at IRW 2006, has been on my desktop for weeks, and I take it as the most challenging food for thought currently available about the Semantic Web. If you have not yet read it, you should now.
There is only one point on which I would argue. Pat holds that reference can be made by ostention (gesticulation showing what you are about) or description. All Pat writes thereafter about description being inherently ambiguous, I strongly agree with : disambiguation being a contextual process, the more precise the description, the more ambiguity you get, and so on.
But I would hold that ostention is as ambiguous as description, so that reference is ambiguous in nature whatever the way it's done.
Suppose I am holding a book and ask you : "Have you read this?". The reference to "this" is by ostention, since I seem to hold and show "this". But the "ostentatum" indicated by "this" is actually some copy of some edition of some book. Does "this" refer to this specific copy, which happens to be my own personal copy (maybe annotated in some way), or is the referent the particular edition of which this specific copy is a sample, or is it the abstract entity, the book independent of any physical support, of which what I am currently holding happens to be some physical avatar? Every one of those interpretations is meaningful, and only the context of the conversation might disambiguate. So even with ostention, there is ambiguity left.