- From: Nathan <nathan@webr3.org>
- Date: Thu, 13 Jan 2011 11:50:14 +0000
- To: Martin Hepp <martin.hepp@ebusiness-unibw.org>
- CC: public-lod@w3.org
wow, typo's to the point of being incomprehensible! fixed: Nathan wrote: > Martin Hepp wrote: >> Hi Nathan: >> >>> There are other ways of looking at this, remembering we're in the >>> realm of machine readable information and the context of RDF. >>> rdfs:seeAlso is used to indicate a resource O which may provide >>> additional information about the resource S - information in this >>> context being rdf, information for the machine - so we can say that >>> if O points to a resource that doesn't contain any information at all >>> (no rdf, or isn't the subject of any statements) then we've created a >>> meaningless statement, it may as well be { S rdfs:seeAlso [] } >>> >>> One could easily suggest that it's good for RDF Schema properties to >>> have some use in RDF, and thus that if rdfs:seeAlso is used in a >>> statement, that it should point to some "information", some rdf for >>> the machine, otherwise it's a bit of a pointless property. >>> >>> Given the above, we could take the meaning of the sentence "no >>> constraints are placed on the format of those representations" and >>> assert that this simply means that RDF/XML is not required, and that >>> any RDF format can be used. >> >> I don't buy in to restricting the meaning of "data" in the context of >> RDF to "RDF data". If the subject or object of RDF triples can be any >> Web resource (information and non-information resource), then the >> range of rdfs:seeAlso should also include information resources (i.e., >> data) of a variety of conceptual and syntactic forms. > > > The "data" part of "linked data" is not generic, machine accessible != > machine understandable, and that's what this is all about. > > "linked data" is not some term for data with links, it's an engineered > protocol which has constraints and requirements to make the whole thing > work. > > We cannot build a web of data (machine understandable dereferencable > data) without these constraints. > >> And PDF, HTML without RDFa as well as images clearly qualify as data. >> They are also clearly machine-accessible. If you are still not >> convinced: What about CSV files or text files containing ACE >> (controlled English), or OData / GData? > > I'm far from convinced, and have discussed this at length w/ Kingsley > and others. > > A three column CSV is not linked data, yes you can take linked data and > format it in a 3 column CSV, and yes with some out of band knowledge > about a particular CSV you can /convert it to/ to RDF, this is not true > for /all/ csv files and only ever works if you have prior knowledge of > the particular file being considered - that is to say, we can't build a > web of data by publishing csv files, or traverse a web of data by > setting our Accept headers to "text/csv" and hoping that any data > received matches our three column constraints (and hoping again when it > does that it actually is something we can use and not just "x x x"). The > same is true of text files containing ACE. > > As for OData and GData, sure it is more linky, and looks more like RDF, > but it's not, and the rabbit hole runs much deeper with these two, but > essentially it's the difference between people making statements with > open world semantics and people having RDF gleaned from data they've put > out which may take on a different meaning when in RDF, other than that > which was intended. > > Ultimately, a big part of the linked data protocol is having machine > readable and understandable data in negotiable well defined formats > available at dereferencable http and https scheme URIs - if you drop any > one of those elements it's simply not "linked data" > > Perhaps this points to a need to standardize Linked Data as a protocol. > > Best, > > Nathan >
Received on Thursday, 13 January 2011 11:52:21 UTC