- From: Kingsley Idehen <kidehen@openlinksw.com>
- Date: Fri, 24 Aug 2012 07:32:33 -0400
- To: public-rdf-wg@w3.org
- Message-ID: <50376651.1020108@openlinksw.com>
On 8/24/12 7:10 AM, Sandro Hawke wrote: > On 08/24/2012 05:31 AM, Richard Cyganiak wrote: >> Sandro, >> >> On 24 Aug 2012, at 03:53, Sandro Hawke wrote: >>> People will need some way linguistically to distinguish X from Y >>> People will instinctively say X to clarify they mean Y >>> People rarely mean to only be talking about X, and when they do, >>> they should put the word Y in there >>> People should be able to use X when they want to clarify they're >>> talking about Y >> That kind of argument is irrelevant. People talk the way they talk. >> They won't pay attention to what we write anyways for the most part. >> We're not in the business of helping them to express themselves. >> >> We are in the business of extending an existing technical >> specification with clear definitions of a few additional concepts in >> order to promote consistency between W3C specifications and to >> promote interoperability between implementations that already use >> these concepts in some form. >> >> We'll never get anywhere with this discussion if we entertain the >> crazy notion that we can magically solve all uncertainty and >> enlighten the RDF community with a Great Global Renaming. > > That's a strawman. I'm not saying names will magically solve > anything. It sounds like our disagreement is a matter of degree. I > believe our choice of terms will affect the quality & uptake of our > specs by X%, while you believe it is a smaller amount Y%. Perhaps X=30 > and Y=10. > > This is complicated by the fact that names interact with mental > models, so sometimes when we're discussing names, I think it turns out > to be a proxy for mental models. And as we change our models, our > opinions on the best names are likely to change. > > So, let's put this back in the box for now, and hopefully when we've > got the model solved, we can spend one telecon talking over proposals > and make a final decision. (I suppose we should give it an ISSUE > number, or broaden ISSUE-14 to include this.) > > I updated http://www.w3.org/2011/rdf-wg/wiki/Graph_Terminology and made > http://www.w3.org/2011/rdf-wg/wiki/Graph_Terminology/Options and I'm > quite happy to let the matter drop for as long as possible. > > -- Sandro Sandro, How would you map g-box, g-snap, and g-text in formal relational DBMS terminology? Such a mapping would help many. Basically, mapping to relations, sets of tuples, and notation. Kingsley > >> Best, >> Richard >> >> >> On 24 Aug 2012, at 03:53, Sandro Hawke wrote: >> >>> On 08/23/2012 11:22 AM, Richard Cyganiak wrote: >>>> On 23 Aug 2012, at 16:00, Sandro Hawke wrote: >>>>>> You proposed to redefine "graph" by splitting it into two >>>>>> separate concepts, a mutable and an immutable one. >>>>>> >>>>>> I propose to instead redefine "named graph" in the same way, by >>>>>> splitting it into two separate concepts, a mutable and immutable >>>>>> one. >>>>> You lost me here, sorry. What's the use case for an immutable >>>>> named graph? >>>> I guess I should have said "abstract named graph", sorry if that >>>> caused confusion. Abstract IRI-graph-pairs. The thing that SPARQL >>>> queries operate over. >>>> >>>>> And it sounds like you're suggesting "mutable named graph" as the >>>>> official term for g-box. Is that right? >>>> Almost. My definition of "mutable named graph" would be: >>>> >>>> "A *mutable named graph* is a resource, denoted by an IRI, that has >>>> a mutable association with an (abstract, immutable) RDF graph. The >>>> RDF graph is also known as the *state* of the mutable named graph." >>>> >>>> The key points are: >>>> >>>> 1) we insist that it is a resource, so the kind of thing denoted by >>>> IRIs >>>> 2) we insist that it is actually denoted by some IRI >>>> 3) it essentially has a mutable slot that contains an RDF graph >>>> >>>> This means it can cover both the terms "RDF space/g-box" and the >>>> term "(name, slot) pair" from the diagram in [1]. >>>> >>>> I repeat my assertion that there is no need to ever talk about >>>> unnamed g-boxes. >>> Yeah, this makes sense, but it's not my first or second choice in >>> naming proposals. Probably wouldn't help to go into why/why not at >>> this point. >>> >>>>>>> I think the key elements are : (1) we stop using "RDF Graph" as the >>>>>>> canonical, precise term for a g-snap; >>>>>> I disagree; "RDF graph" is a perfectly fine term. >>>>> I wish. I can live with it, but I think it's hardly "fine". >>>>> People use it wrong all the time; they say "RDF graph" and mean a >>>>> mutable and/or distinct set of RDF triples. >>>> I think by actually defining proper terms for these other things, >>>> and by clarifying that "graph" can mean "any of the above", we make >>>> a solid step towards improving the situation. >>> I think you're saying "RDF graph"==g-snap; "graph"=g-snap/or/g-box. >>> >>> I have a problem with this. I think people will need some way >>> linguistically to distinguish "graph" in the RDF world from "graph" >>> in the wider world, and the natural way to do that is to add the >>> modifier, "RDF". So people will instinctively say "RDF graph" to >>> clarify they mean "graph" in the RDF sense (not a bar chart or >>> something). But with your proposal, they've now accidentally >>> changed to talking about g-snaps. >>> >>> I think people rarely mean to only be talking about g-snaps, and >>> when they do, they can/should put the word "abstract" in there. I >>> also think the presence or absence of the modifier "RDF" shouldn't >>> affect the semantics of the term -- people should be able to use it >>> when they want to clarify they're talking about RDF, without it >>> otherwise affecting the meaning. >>> >>> -- Sandro >>> >>>> Best, >>>> Richard >>>> >>>> [1] http://www.w3.org/2012/08/RDFNG.html#fig1 >>>> >>>> >>>> >>>>> I'm not saying we have to solve this problem, or that we can, but >>>>> I think it would be helpful if we could and I think this proposal >>>>> is our best bet. >>>>> >>>>> -- Sandro >>>>> >>>>>> But we can stress that "RDF graph" is an abstract, unnamed, >>>>>> immutable graph, and that when we talk about "graphs" in general >>>>>> then we may sometimes mean named ones that may or may not be >>>>>> mutable. >>>>>> >>>>>>> (2) we pick terms for g-box and g-snap that convey the idea that >>>>>>> they are two different kinds of "graphs"; >>>>>> I disagree; I believe that there is never any need to talk about >>>>>> *unnamed* g-boxes; all the g-boxes we want to talk about are >>>>>> named. Therefore, a term like "mutable named graph" is sufficient >>>>>> to say all that needs to be said about g-boxes. >>>>>> >>>>>>> (3) we use "graph" if/when we don't mind being ambiguous about >>>>>>> g-box/g-snap. >>>>>> I'd rephrase that: We can use "graph" if/when we don't mind being >>>>>> ambiguous about g-snap/abstract-named-graph/mutable-named-graph. >>>>>> For example when we say, "SPARQL Update can be used to copy data >>>>>> from one graph to another". In that case we mean >>>>>> mutable-named-graph. >>>>>> >>>>>>> On your details.... let me start with: to you, can you have a >>>>>>> named >>>>>>> graph that's not in a dataset (or graph store)? >>>>>> As defined in SPARQL (named graph == IRI-graph-pair), no. >>>>>> >>>>>> But if we allow a term such as "mutable named graph", then yes. A >>>>>> Turtle document on the Web is a "mutable named graph", in that >>>>>> sense. It doesn't have to be in any particular dataset. Well, >>>>>> it's in the Web, and for me it makes sense to speak of the entire >>>>>> web as a "mutable RDF dataset". >>>>>> >>>>>> Best, >>>>>> Richard >>>>>> >>>>>> >>>>>>> I don't usually hear the term used outside SPARQL, so I don't >>>>>>> have much of an ear for that usage. >>>>>> -- Sandro >>>>>> >>>>>>> Best, >>>>>>> Richard >>>>>>> >>>>>>> >>>>>>> >>>>>>> On 22 Aug 2012, at 18:07, Sandro Hawke wrote: >>>>>>> >>>>>>>> On 08/21/2012 03:33 AM, Andy Seaborne wrote: >>>>>>>>> On 20/08/12 16:30, Sandro Hawke wrote: >>>>>>>>>> If it wouldn't cause SPARQL too many problems, I'd suggest we >>>>>>>>>> should do >>>>>>>>>> the same with dataset, and even allow a dataset to be a kind >>>>>>>>>> of graph, I >>>>>>>>>> think, so that the world at large can use the word term "RDF >>>>>>>>>> dataset" >>>>>>>>>> for any collection of RDF data (whether or not it's segmented >>>>>>>>>> into named >>>>>>>>>> graphs). >>>>>>>>> That would be problematic. "RDF Dataset" is a specifically >>>>>>>>> defined term. "Dataset" we can be loose about (c.f. VoiD) ; >>>>>>>>> "RDF Dataset" is stressing the tie to a particular >>>>>>>>> definition. You might as well mix properties and triples if >>>>>>>>> you're going to mix things of different "shape". >>>>>>>> In the telecon, I mentioned on irc the term "bacronym" but what >>>>>>>> I meant was "retronym". These are terms like "cow milk" that >>>>>>>> arise once some term ("milk") becomes ambiguous (eg because of >>>>>>>> soy milk, almond milk, rice milk, etc). See >>>>>>>> >>>>>>>> I take the "radical proposal" to be the recognition that some >>>>>>>> terms are ambiguous and we need to make retronyms to >>>>>>>> disambiguate them. >>>>>>>> >>>>>>>> Here's a revised proposal: >>>>>>>> >>>>>>>> - We pick terms like "Abstract RDF Graph" (gsnap) and >>>>>>>> "Maintained RDF Graph" (gbox) that fit the retronym model. It >>>>>>>> makes it easy, when someone says "graph" or "RDF Graph", to >>>>>>>> think/ask, "do you mean abstract or maintained?" (I don't >>>>>>>> find these terms quite as ontologically comfortable as g-snap >>>>>>>> and g-box/space/data-source, because it makes them both be >>>>>>>> subclasses of "graph", but I think this approach works better >>>>>>>> for the community.) >>>>>>>> >>>>>>>> - We clarify that in all W3C specs to date, "RDF Graph" >>>>>>>> means "Abstract RDF Graph" >>>>>>>> >>>>>>>> - Going forward, we avoid using the term "RDF Graph", using >>>>>>>> either Abstract Graph or Maintained Graph (with or without >>>>>>>> "RDF" in there). Or just "graph" when we don't care which kind. >>>>>>>> >>>>>>>> I think that much of the confusion around the term "named >>>>>>>> graph" comes from a lack of clarity around whether what is >>>>>>>> meant is a "named abstract graph" or a "named maintained >>>>>>>> graph". I think the latter is much more common; the >>>>>>>> difference doesn't manifest in SPARQL 1.0 because it doesn't >>>>>>>> consider the idea of data changing. In my mind, this proposal >>>>>>>> is our best chance for being able to coherently keep using the >>>>>>>> term "named graph", which seems to be very popular. >>>>>>>> >>>>>>>> BTW, I think we might also want to define "Frozen" graph, which >>>>>>>> is a maintained graph in the sense that it exists in a >>>>>>>> computer's storage, but which is required to never change. >>>>>>>> This is, I think, mostly what PROV wants to use. >>>>>>>> >>>>>>>> -- Sandro >>>>>>>> >>> >> > > > > -- Regards, Kingsley Idehen Founder & CEO OpenLink Software Company Web: http://www.openlinksw.com Personal Weblog: http://www.openlinksw.com/blog/~kidehen Twitter/Identi.ca handle: @kidehen Google+ Profile: https://plus.google.com/112399767740508618350/about LinkedIn Profile: http://www.linkedin.com/in/kidehen
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Received on Friday, 24 August 2012 11:30:58 UTC