Re: Linked Data, Blank Nodes and Graph Names
re On Thu, Apr 07, 2011 at 06:45:55PM +0100, Nathan wrote: To cut a long story short, blank nodes are a bit of a PITA to work with, Yes. - would you be happy to give up blank nodes? No - just the [] syntax? I am not sure if I understand that. I know that syntax from SPARQL and N3. I see no reason to remove it from SPARQL. - do you always have a name for your graphs? (for instance when published on the web, the URL you GET, and when in a store, the ?G of the quad? Not always. 4) create a subset of RDF which does have a way of differentiating blank nodes from URI-References, where each blank node is named persistently as something like ( graph-name , _:b1 ), This seems to be a way of skolemizing using the graph name. I would prefer a way of skolemizing that does not depend on the graph name and can be done by producer *and* consumer of RDF on a voluntary base. It should be a standard with reference implementations in all important languages for: -generating a skolem URI -converting an unskolemized RDF serialization to a skolemized one -converting a skolemized RDF serialization to an unskolemized one It is important that skolem URIs would be recognizeable. Regards, Michael Brunnbauer -- ++ Michael Brunnbauer ++ netEstate GmbH ++ Geisenhausener Straße 11a ++ 81379 München ++ Tel +49 89 32 19 77 80 ++ Fax +49 89 32 19 77 89 ++ E-Mail bru...@netestate.de ++ http://www.netestate.de/ ++ ++ Sitz: München, HRB Nr.142452 (Handelsregister B München) ++ USt-IdNr. DE221033342 ++ Geschäftsführer: Michael Brunnbauer, Franz Brunnbauer ++ Prokurist: Dipl. Kfm. (Univ.) Markus Hendel
[ANN] Win 450USD for the best Personal Data Mashup!
Your computer is overflowing with applications for managing your data: your photos, your documents, your calendar, your email, etc. On the other side of your internet connection, the web is overflowing with services for creating, managing, and sharing many of the same things. We believe that Semantic Technology can be used for linking, categorizing and combining the data from all these sources, giving you an overall view that no single application can match. If you agree - come to PSD2011 - show us how and get rich(*) and famous! http://semanticweb.org/wiki/PSD2011Challenge -- the PSD2010 Organizers, -- Gunnar Aastrand Grimnes DFKI GmbH http://www.dfki.uni-kl.de/~grimnes
Re: How To Do Deal with the Subjective Issue of Data Quality?
On 4/7/11 8:59 PM, Michael F Uschold wrote: I subscribe to the doctrine that data quality is like beauty it lies strictly in the eyes of the beholder Interesting position. Seems a bit post-modernesque... I think there is some truth here, just like beauty in a program, or an building architecture, or an ontology -- people defninitely have different opinions. However, IMHO, it would be dangerous to conclude that all or even the significant majority of issues of data quality are just matters of opinion. This would prevent doing the hard work of identifying some core principles that most people can agree on most of the time. I bet there are many many cases where you could ask people of diverse opinions and get clear agreement by asking the simple question: is this data high or low quality? So maybe its like porn, you can't define it, but most people agree when it is or isn't. We all have individual opinions, achieving broader group acceptance is where the group mind aspect comes into play. Thus, the group/community ultimately establishes the quality metrics for its particular context. I think it's a generally accepted opinion that there are no absolute truths i.e., at best we have claims. The Web and its emerging Linked Data dimension simply reflect this reality (IMHO) :-) Kingsley Michael On Thu, Apr 7, 2011 at 11:06 AM, Kingsley Idehen kide...@openlinksw.com mailto:kide...@openlinksw.com wrote: All, Apologies for cross posting this repeatedly. I think I have a typo free heading for this topic. Increasingly, the issue of data quality pops up as an impediment to Linked Data value proposition comprehension and eventual exploitation. The same issue even appears to emerge in conversations that relate to sense making endeavors that benefit from things such as OWL reasoning e.g., when resolving the multiple Identifiers with a common Referent via owl:sameAs or exploitation of fuzzy rules based on InverseFunctionProperty relations. Personally, I subscribe to the doctrine that data quality is like beauty it lies strictly in the eyes of the beholder i.e., a function of said beholders context lenses. I am posting primarily to open up a discussion thread for this important topic. -- Regards, Kingsley Idehen President CEO OpenLink Software Web: http://www.openlinksw.com Weblog: http://www.openlinksw.com/blog/~kidehen http://www.openlinksw.com/blog/%7Ekidehen Twitter/Identi.ca: kidehen -- Michael Uschold, PhD Senior Ontology Consultant, Semantic Arts LinkedIn: http://tr.im/limfu Skype, Twitter: UscholdM -- Regards, Kingsley Idehen President CEO OpenLink Software Web: http://www.openlinksw.com Weblog: http://www.openlinksw.com/blog/~kidehen Twitter/Identi.ca: kidehen
Re: How To Do Deal with the Subjective Issue of Data Quality?
On 4/7/11 11:36 PM, Patrick Logan wrote: I believe Data Wikis will go long way to crowd sourcing data reconciliation. Of course, for that to happen you need access control lists (ACLs) and verifiable identity, which is why the WebID protocol (an application of Linked Data) is so important to this whole topic of subjective data quality. I am not familiar with that, but I'll look at it. Off the cuff, I have doubts an ACLs are appropriate for the web, where the nature of URLs seems to have a built-in affinity to a capability-based access control. By Data Wiki I also imply the ability to read and write data (in triple form re. Linked Data variety) to and from Addresses (URLs) where WebID delivers: 1. Verifiable Identity 2. ACL functionality that leverages Trust Semantics . Thus, like Wikipedia, folks create data at will and naturally debate controversial items. But unlike Wikipedia this isn't about blurb, solely. It's about raw data and the zeitgeist around each data object. All of this make conflict resolution somewhat easier to handle, at least relative to Wikipedia, mailing lists, and other realms with discussion/conversation dimensions. -- Regards, Kingsley Idehen President CEO OpenLink Software Web: http://www.openlinksw.com Weblog: http://www.openlinksw.com/blog/~kidehen Twitter/Identi.ca: kidehen
Re: Quick reality check please
(catching up) On 2 Apr 2011, at 19:54, Hugh Glaser wrote: 1. xsd:string in RDF must die. It's one of those completely and utterly useless pieces of rubbish that litter the RDF specs. Perhaps you could tell us what you really think :-) 2. If you publish in multiple languages, then perhaps it's a good idea to include a plain literal in a “default language” without a language tag, to make SPARQLing easy. So I would guess from this that it could be that some documents could be adjusted to recommend this sort of thing. Certainly for 2; is it the case for 1 that technically there should be a type? The first issue is on the agenda of the new RDF WG: http://www.w3.org/2011/rdf-wg/track/issues/12 With the second issue it's not so clear what to do about it. It's a question of good practice, and I'm not aware of any document where that recommendation could be easily added. Best, Richard
Music and Semantic Web panel, London, 13th of May
Hello! We're organising a panel discussion on music and the semantic web in London, on the 13th of May, as part of the 130th AES convention: http://www.aes.org/events/130/workshops/?ID=2639 Best regards, and hopefully see some of you there! Yves
Re: Quick reality check please
On Fri, Apr 8, 2011 at 1:21 PM, Richard Cyganiak rich...@cyganiak.de wrote: With the second issue it's not so clear what to do about it. It's a question of good practice, and I'm not aware of any document where that recommendation could be easily added. Maybe it could be written up as a pattern for the Linked Data Patterns book? http://patterns.dataincubator.org/ Ian
Re: Take 2: How To Do with deal with the Subjective Matter of Data Quality?
On Apr 7, 2011, at 7:45 PM, Deborah MacPherson wrote: I think data quality conforms to metrics and repeatable processes. Now we're getting somewhere! Certainly one key to dealing with the subjective matter of data quality is to start to make data quality issues more *objective*. Everyone can have their own opinion about what constitutes quality, but in the Web of linked data those opinions should be documented, in the form of metadata on evaluation criteria, metrics, processes, etc. (PICS anyone?) associated with the data. Even if there isn't agreement on what those criteria, etc. are, there would be a better basis for grappling with the disagreements.
Re: Take 2: How To Do with deal with the Subjective Matter of Data Quality?
On 4/8/11 2:25 PM, Frank Manola wrote: On Apr 7, 2011, at 7:45 PM, Deborah MacPherson wrote: I think data quality conforms to metrics and repeatable processes. Now we're getting somewhere! Certainly one key to dealing with the subjective matter of data quality is to start to make data quality issues more *objective*. Yes, and go one step further by making the *objectivity* part of the data. Basically, discussion/conversation/debates about the data should be part of the zeitgeist of any Data Object or collection of Data Objects. Everyone can have their own opinion about what constitutes quality, but in the Web of linked data those opinions should be documented, in the form of metadata on evaluation criteria, metrics, processes, etc. (PICS anyone?) associated with the data. Yep! As stated above. Even if there isn't agreement on what those criteria, etc. are, there would be a better basis for grappling with the disagreements. Agreeing to Disagree is one of the most powerful aspects of the Web and the emerging Web of Linked Data :-) -- Regards, Kingsley Idehen President CEO OpenLink Software Web: http://www.openlinksw.com Weblog: http://www.openlinksw.com/blog/~kidehen Twitter/Identi.ca: kidehen
