- From: Richard Cyganiak <richard@cyganiak.de>
- Date: Wed, 7 Mar 2007 17:25:46 +0100
- To: Golda Velez <w3@webglimpse.org>
- Cc: semantic-web@w3.org
Golda, On 7 Mar 2007, at 17:37, Golda Velez wrote: > - about the ISBN: stuff. Of course we should be able to use those > identifiers, but yes they need a namespace otherwise someone will be > referring to the "International Society for Butter Nuts". That can > be solved > if the info: people or someone else offers to provide a stable URL > referencing them. Like, info://ns.info/2007/isbn/NNNNNNN > If the namespace owner is trusted and says they will not reinvent > the meaning > of that URL, that's good enough. It would be nice if w3 or one > other central > org was in the habit of providing such urls. Note a web page or HTTP > anything is not necessary if its not a full ontology - its just a > URL to ref > a concept! If it's OK with you that the URI is not resolvable, then why not just use urn:isbn:XXXXX, it's a standard [1]. Of course it would be nice if someone would provide HTTP URIs that actually return useful data. We tried to do this with the RDF Book Mashup [2], using URIs like this: http://www4.wiwiss.fu-berlin.de/bookmashup/books/006251587X It uses the Amazon API to retrieve some data about the book. But as you say, a highly trusted namespace owner would be better. I don't think this is W3C's job though. Setting up an HTTP server for this kind of stuff isn't *that* hard. > - tools to go back and forth from the RDF world for us old sql > programmers. I > have a semi-semantic web type app meant for joe user that has 8000+ > categories and 80000+ items that can all relate to each other, and > needs > flexible and fast ways to display subsets. So I have it all in > mysql. There > is a table with a RELATION field with a small set of allowed > relations. It > seems to me there should eventually be simple tools for porting > this kind of > data into and out of RDF. Not everyone wants to use RDF as the > back end all > the time..and not all the features of ontologies are needed for all > applications, but any valid semantic data should be able to be > exposed for > use. Very true, and a number of applications exist for this purpose. See [3] for a list. (I'm one of the authors of D2RQ and D2R Server, which I think are fairly good at solving this kind of problem, though not yet as simple as I'd like. Check out [4] for a bibliography database of 800k+ records mapped to RDF using D2R Server.) Yours, Richard [1] http://www.ietf.org/rfc/rfc3187.txt [2] http://www4.wiwiss.fu-berlin.de/bookmashup/ [3] http://esw.w3.org/topic/RdfAndSql [4] http://www4.wiwiss.fu-berlin.de/dblp/ > - it seems to me some relations are pretty universal because they are > abstract. I'd like to see a lot of reuse in different ontologies > of things > like > IS_LOCALIZATION_OF > IS_PERSONALIZATION_OF > DEPENDS_ON > CREATED_BY > and so on, these types of words are abstractions humans can relate > to totally > different fields, and could be used pretty universally, no? > > Well, as usual I've probably missed the point, but anyway once all > the semweb > stuff is simple enough for me to use then you know you have something > happening. > > Last point, probably showing my lack of research - so where is the > registration place with simple categories for all semweb related > things? > > bye all > > --Golda > > ps I wrote a more in-depth (even than the above lengthy mail) > explanation of > these kind of points at http://webglimpse.net/Mapping.pdf . mainly > its an > argument for the info: people or someone trusted to make versioned, > extensible concept urls for standard concept schemes that haven't been > webified yet. > > > > > On Wednesday 07 March 2007 01:20, matthew.west@shell.com wrote: >> <snip> >>> An agent plays a role in many different >>> overlapping communities. When I tag a photo as being of my >>> car, or I >>> agree to use my car in a car pool, or when I register the car with >>> the Registry of Motor Vehicles, I probably use different >>> ontologies. There is some finite effort it would take to >>> integrate >>> the ontologies, to establish some OWL (or rules, etc) to link them. >>> >>> - Everyone is encouraged to reuse other people's classes and >>> properties to the greatest extent they can. >> >> MW: One of the counterbalances I find to this is that it is often >> easier/cheaper to reinvent classes than find them (usually lots of >> versions) and decide if any of them really meet your needs. I know I >> see a lot of reinvention. >> >>> - Some ontologies will already exist and by publicly shred by many, >>> such as ical:dtstart, geo:longitude, etc. This is the single global >>> community. >> >> MW: This is a pure guess, but if we take longitude as an example I >> would be very surprised if there were not at least 100 publicly >> available ontologies that defined longitude. To reduce this, one >> of the things I think we need to do is to develop a sense of >> authoritative source. We need to ask ourselves the question: who >> "owns" this? What is *their* name/definition? This is something we >> try to do with out own reference data. So we recognise ISO country >> codes, rather than invent our own, we recognise a companies product >> name/code when we buy their product, and the companies registered >> name and number, rather than our abbreviation or version of it. >> >>> - Some ontologies will be established by smaller communities of many >>> sizes. >>> >>> Why do I think the structure should be will be fractal? Clearly >>> there will be many more small communities, local ontologies, than >>> global ones. Why a 1/f distribution? Well, it seems to occur in many >>> systems including the web, and may be optimal for some problems. >>> That we should design for a fractal distribution of ontologies is a >>> hunch. But it does solve the issue you raise. Some aspects of the >>> web have been shown to be fractal already. >>> >>> Here are some properties of the interconnections: >>> >>> - The connections between the ontologies may be made after their >>> creation, not necessarily involving the original ontology designers. >>> - There is a cost of connecting ontologies, figuring out how they >>> connect, which people will pay when and only when they need the >>> benefit of extra interoperability. >>> - Sometimes when connecting ontologies, it is so awkward there is >>> pressure to change the terms that one community uses to fit >>> in better >>> with the other community. Again, a finite cost to make the change, >>> against a benefit or more interop. >> >> MW: This is close to the dynamic view that I see. I see ontologies >> start in isolation and then grow. Eventually, they bump into adjacent >> ontologies that have also been growing (many will die of course). >> >> MW: When enough ontologies overlap in a sufficiently annoying and >> expensive way, an effort is undertaken to integrate these ontologies >> to better support integration. This produces an increased centre of >> gravity, and almost immediately small ontologies will spring up at >> the edges, and bigger ontologies will bump into other big ontologies. >> >> MW: This process repeats, as far as I can see indefinitely. I observe >> that - within Shell at least - the time between integrating at one >> level and integrating at the next level up is about 10 years. >>> >>>> Hence the need for a universal model as a common denominator. But >>>> it is striking that the word "interconnection" was used, rather >>>> than "integration". Interconnection reminds me of EAI [2], so hub- >>>> based or point-to-point, where Semantic Web integration (as I >>>> understand it) involves a web-based distributed data base. >>> >>> Yes, if web-based means an overlapping set of many ontologies in a >>> fractal distribution. >>> In his fractal tangle, there wil be several recurring patterns at >>> different scales. >>> One pattern is a local integration within (say) an enterprise, which >>> starts point-point (problems scale as n^2) and then shifts with EIA >>> to a hub-and-spoke as you say, where the effort scales as N. Then >>> the hub is converted to use RDF, and that means the hub then plugs >>> into a external bus, as it connects to shared ontologies. >> >> MW: That same kinds of things will happen with the shared ontologies >> as with the enterprise ontologies (moving to a hub and spoke model >> requires an integrating ontology that at least spans the shared >> data). >>> >>> >>> >>>> >>>> Keeping in mind that, as I wrote before in this thread, >>> application >>>> systems store a lot of implicit data (or actually don't store >>>> them), the direct mapping of their data to the SW formats will >>>> cause more problems than its solves. They are based on their own >>>> proprietary data model, and these are unintelligible for other, >>>> equally proprietary, data models. >>>> >>>> The thing puzzling me is how the SW community can see what >>> I cannot >>>> see, and that is how on earth you can achieve what your Activity >>>> Statement says, without such a standard generic data model and >>>> derived standard reference data (taxonomy and ontology). But >>>> perhaps not many SW-ers bother about the need of universal >>>> integration, and are happily operating within their own subdomain, >>>> such as FOAF. >>> >>> So the idea is that in any one message, some of the terms will be >>> from a global ontology, some from subdomains. >> >> MW: Well if this means that we go out to the authoritative source for >> reference data, rather than reinventing it, then that would be >> consistent with what I was saying above. But at the moment, the >> problem >> I see is that just about everyone thinks they have the right to be >> an authoritative source on whatever they please. This is not useful. >> >>> The amount of data which can be reused by another agent will depend >>> on how many communities they have in common, how many >>> ontologies they >>> share. >>> >>> In other words, one global ontology is not a solution to the >>> problem, >> >> MW: But interestingly, something that was the sum of the >> authoritative >> sources I have been talking about, would be something like a global >> ontology (but not the only one of course - just a dominant one). >> >>> and a local subdomain is not a solution either. But if each agent >>> has uses a mix of a few ontologies of different scale, that is forms >>> a global solution to the problem. >> >> MW: I'm not convinced about this, though I will concede that >> authoritative sources might have small or large ontologies with >> variation >> in the size and spread of their user base. However, I am quite >> confident >> that we will only get there if we can find a way to reduce the use >> of non-authoritative sources. Of course the web is the only chance we >> have of being able to share these authoritative sources effectively. >>> >>> Tim. >>> >>>> >>>> Can anybody enlighten me, at least by pointing to some useful >>>> links? >>>> >>> >>> ummm http://www.w3.org/DesignIssues/Fractal.html to which I might >>> add this explanation some time. >>> >>> >>> >>>> Regards, >>>> Hans >>>> >>>> PS The above does not mean that I have no faith in the SW. On the >>>> contrary, I preach the SW gospel. But I just want to understand >>>> where it is moving to. >>>> >>>> [1] http://www.w3.org/2001/sw/Activity >>>> [2] http://en.wikipedia.org/wiki/Enterprise_Application_Integration >>>> >>>> ____________________ >>>> OntoConsult >>>> Hans Teijgeler >>>> ISO 15926 specialist >>>> Netherlands >>>> +31-72-509 2005 >>>> www.InfowebML.ws >>>> hans.teijgeler@quicknet.nl >>>> >>>> >>>> >>>> -- >>>> No virus found in this outgoing message. >>>> Checked by AVG Free Edition. >>>> Version: 7.5.446 / Virus Database: 268.18.6/708 - Release Date: 02- >>>> Mar-07 16:19 >>> >>> >>> >> >> > > -- > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Golda Velez http://goldavelez.info > http://bTucson.com be Tucson - share your info! > http://Webglimpse.Net search engine software > cell: (520) 440-1420 > "Help organize the world - index your own corner of the web!" > >
Received on Wednesday, 7 March 2007 16:25:56 UTC