W3C home > Mailing lists > Public > semantic-web@w3.org > February 2017

Re: Which semantics?

From: Pat Hayes <phayes@ihmc.us>
Date: Sun, 26 Feb 2017 22:14:40 -0600
Message-Id: <56D63A5E-3490-4E9D-AD9C-D268B2E20A41@ihmc.us>
Cc: pragmaticweb@lists.spline.inf.fu-berlin.de, public-rww <public-rww@w3.org>, semantic-web@w3.org
To: Sebastian Samaruga <ssamarug@gmail.com>
Thanks for clarifying, but I think you are misguided. You want to “use RDF" but you don’t want to pay any attention to the RDF specifications, do I have that right? If so, you are not using RDF, but mis-using it. If you proceed, I would strongly suggest that you do not use any RDF terminology to describe what you are doing, or RDF tools to process whatever it is you finish up building. The entire point and purpose of RDF is to provide a standard notation for information exchange on the Web. If you use the RDF data model without also conforming to the RDF standards (including the RDF semantics, which is a normative part of the standard) then you will not be contributing to this global effort, and whatever you finish up doing will not be usable as RDF, will probably break if processed by RDF engines, and will cause only pain and confusion. (An analogy might be to suggest using HTML syntax as a musical notation, ignoring what browsers do with it.) 

You say you are a SW beginner, but surely the first thing a beginner should do is to learn how to use the basic tools (in the SW case, RDF - or JSON-LD if you prefer - and linked data conventions) rather than deliberately ignoring the operation manual and setting out to mis-use them. 

You say that what you are doing is “not just RDF”. You mis-speak, It is not RDF at all. 

Best wishes

Pat Hayes


> On Feb 25, 2017, at 1:45 AM, Sebastian Samaruga <ssamarug@gmail.com> wrote:
> 
> I'll repost this message again because it seems that maybe I was not clear enough or misunderstood. I don't want to reinvent anything, not even temporal logic or ontology merging. What I'd like is to have all this implemented, struggling the RDF data model in ways not conventional at all except by using it as a kind of universal datasource format and being able to expose ontologies but, internally, performing sorting, merge and many kinds of augmentation using BI / Big Data learning, analysis and mining techniques, not only 'pure' RDF / OWL inference.
> 
> Note that the document(s) included are just an enumeration of topics of what the aspects of a model built for this purpose could look like.
> 
> First, thanks everybody for your interest in helping me. I'll be reviewing each comment and links. The question is, I'm a SW beginner but maybe I was not expressing me correctly.
> 
> I'm not trying to do 'canonical' Semantic Web, Linked Data not even RDF. I just take RDF quads as a simple serialization mechanism and try to build upon that what a 'relational model' could be for a traditional database.
> 
> For this I encode lots of metadata regarding the original input 'RDF' (this is because any data source data I'll use can be encoded as RDF) and arrange metamodels which aggregate and infer knowledge about original data.
> 
> I try to merge and align equivalent resources and statements, perform resource relationships retrieval and comparation and finally I try to sort resources and statements logically and temporally.
> 
> For this I aggregate statement resources into levels and classify those resources using my own kind of type inference. 
> 
> Templates is a concept I use for 'a graph of resources, statements, with types, variables and wildcards also as resources. A Template applied to another resource (Template) may shield another graph.
> 
> Over Templates I build a 'protocol'. Each request/response is a Template (graph) and dialog finishes when each part 'completes' or resolves its corresponding types, variables and wildcards.
> 
> Having a 'protocol' each metamodel layer narrows itself into Facades, another (sub) graph of each level regarding level's kind of constructions (facts, objects, purposes: anOrder, orders, order management).
> 
> All the 'constructions' I've made are not (and not even pretends to be) Semantic Web or RDF standards based. If you read the document please bear this in mind. 
> 
> There I've just laid down spare propositions of 'parts' of this 'relational model' encoded in metadata which, in turn, encodes the layers of models using just three classes.
> 
> It's funny that I've used RDF as a kind of universal input translation mechanism and that it inspired the contexts, kinds and metamodel abstractions somehow. Mostly when I recall almost everyone on these lists telling me I'm wrong, perhaps because I didn't warn them this is something else, not just RDF.
> 
> So, before being misunderstood, I'll share this link which is not a paper, specification, documentation, draft or even complete at all. It is just a TOC, a raw placeholder where the blanks could be filled and corrections be made.
> 
> Available for comments at:
> https://docs.google.com/document/d/1VrvIV4rXyUyGl5jvDAgsEV4GRxX_NvMICgkdnbvj9DQ/edit?usp=drivesdk <https://docs.google.com/document/d/1VrvIV4rXyUyGl5jvDAgsEV4GRxX_NvMICgkdnbvj9DQ/edit?usp=drivesdk>
> 
> The document just does enumerate concepts, some mentioned above. It starts describing the resource data/meta models. It is just titles and a brief explanation. Sorry for posting a so very early 'draft' (dump) but I'm not willing to publish a document but to build a set of 'patterns' for modelling and looking for 'constructive' feedback.
> 
> I'll attach a previous document as a reference for things I mention in the Google doc and that perhaps are not so well defined. The Google doc, once finished, will reflect more coherently all concepts regarding the proposal.
> 
> Thanks,
> Sebastián.
> 
> 
> On Feb 18, 2017 3:01 AM, "Pat Hayes" <phayes@ihmc.us <mailto:phayes@ihmc.us>> wrote:
> 
>> On Feb 15, 2017, at 5:43 AM, Sebastian Samaruga <ssamarug@gmail.com <mailto:ssamarug@gmail.com>> wrote:
>> 
>> OK. But sorry again for my lack of knowledge but does this mean that 'semantic' inference of the kind of 'inferring' that:
>> 
>> http://somedomain.net/people/John <http://somedomain.net/people/John>
>> (is the same as)
>> http://anotherdomain.com/staff/Juan <http://anotherdomain.com/staff/Juan>
>> 
>> is not possible without resorting in previous knowledge
> 
> If I understand you, indeed it is not possible without previous knowledge; but not of dictionaries, but rather of identities. Quite a lot of the information stored in RDF is exactly of this form, expressed using the relational URI owl:sameAs, in the form of an RDF triple.
> 
>> or dictionaries or, even worst, NLP over those URIs? Not even to mention 'inferring' identity between 'The capital of France' and 'Paris' or 100cm / 1meter.
> 
> All such identities must be expressed directly or indirectly in some ontology, probably in the form of an RDF graph. For the first example it might be more useful to simply say that Paris (Subject) is the capital city of (Relation) France (Object) in a single triple, rather than use owl:sameAs. Identity of measure terms has been tackled by ontologies of units and measurements, such as OM (http://www.wurvoc.org/vocabularies/om-1.6/ <http://www.wurvoc.org/vocabularies/om-1.6/>)
> 
>> 
>> Another kind of inference that simply concatenating datasets just not solve is that of 'ordering':
>> 
>> Joe takes his car out.
>> Joe washes his car.
>> Joe takes his car in.
>> 
>> How if the statements comes in any order one could reason about the correct sequence. This will be indispensable for propositional like logic and inference.
> 
> Actually not (indispensable, that is). Logics typically do not use the ordering of statements to encode content. (There is a good reason for this, having to do with how logical inference rules can be stated, but it would take too long to explain.)  To express meaningful orderings, especially time orderings (as here), one must describe the ordering relations explicitly. There is a huge literature on how to use logics to express such things, far more than I can summarize here, but one way to proceed would be to describe things one might call ‘events’ (takings in and out, washings, etc.), classify them into types or categories (corresponding roughly to the English verb) and associate them using ontological relations to times (to get the orderings), subjects, objects, and possibly such things as locations (where it happened) and reasons (why it happened). All of this can be directly written as RDF graphs and reasoned about using RDF or OWL reasoning engines. 
> 
> All of this has been thought about very hard by a very large number of people for about 60 years now. You don’t want to try to re-invent it all, would be my advice. 
> 
> Best wishes
> 
> Pat Hayes
> 
>> 
>> Best,
>> Sebastián.
>> 
>> 
>> 
>> 
>> On Feb 14, 2017 4:20 PM, "Martynas Jusevičius" <martynas@graphity.org <mailto:martynas@graphity.org>> wrote:
>> Sebastian,
>> 
>> I think it is useful to think about the merge operation between datasets.
>> 
>> Here I mean a "physical" merge, where records with the same
>> identifiers become augmented with more data, when multiple datasets
>> are merged together. A "logical", or "semantic" merge, with vocabulary
>> mappings etc., comes on top of that.
>> 
>> So if you take the relational or XML models, there is no generic way
>> to do that. With RDF, there is: you simply concatenate the datasets,
>> because they have a stable structure (triples) and built-in global
>> identifiers (URIs).
>> 
>> That said, you should try approaching things from another end: start
>> building a small but concrete solution and solve problems one by one,
>> instead of overthinking/reinventing the top-down architecture. Until
>> you do that, you will probably not get relevant advice on these
>> mailing lists.
>> 
>> On Tue, Feb 14, 2017 at 6:21 PM, Sebastian Samaruga <ssamarug@gmail.com <mailto:ssamarug@gmail.com>> wrote:
>> > Sorry for me being so ignorant. But what could be called 'semantic' (in the
>> > sense of 'meaning', I suppose) for the current frameworks, at least the
>> > couple I know, available for ontologies of some kind if they could assert
>> > between their instances which statements and resources are equivalent (being
>> > them in a different language/encoding or different 'contextual' terms for
>> > the same subjects for example).
>> >
>> > Another important lack of 'semantics' is ordering (temporal or whatsoever)
>> > where a statement or resource should be treated at least in relation to
>> > their previous or following elements.
>> >
>> > If my last posts where so blurry is because I try to address some of this
>> > issues, besides others, trying no to fall in the promise that adhering to
>> > one format will free us all of any interoperability hassles. Remember a
>> > similar promise from XML: "All we have to do is share DTDs and
>> > interoperate". I'll still trying to give the format a twist (RDF Quads) but
>> > I'll publish a Google Document open for comments.
>> >
>> > Best,
>> > Sebastián.
>> >
> 
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> 
> 
> 
> 
> <Datastore.pdf><Notes.pdf>

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Received on Monday, 27 February 2017 04:15:30 UTC

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