14:25:49 RRSAgent has joined #rdf-wg 14:25:49 logging to http://www.w3.org/2011/04/20-rdf-wg-irc 14:25:51 RRSAgent, make logs world 14:25:51 Zakim has joined #rdf-wg 14:25:53 Zakim, this will be 73394 14:25:53 ok, trackbot; I see SW_RDFWG()11:00AM scheduled to start in 35 minutes 14:25:54 Meeting: RDF Working Group Teleconference 14:25:54 Date: 20 April 2011 14:40:33 AZ has joined #rdf-wg 14:46:09 SteveH has joined #rdf-wg 14:48:12 OlivierCorby has joined #rdf-wg 14:53:50 ivan has joined #rdf-wg 14:54:28 cygri has joined #rdf-wg 14:54:58 Scott has joined #rdf-wg 14:56:44 mbrunati has joined #rdf-wg 14:57:36 SW_RDFWG()11:00AM has now started 14:57:44 +davidwood 14:57:47 Zakim, what's the code 14:57:47 I don't understand 'what's the code', SteveH 14:57:51 Chair: David Wood 14:57:57 Zakim, what is the code? 14:57:57 the conference code is 73394 (tel:+1.617.761.6200 tel:+33.4.26.46.79.03 tel:+44.203.318.0479), SteveH 14:58:00 SteveH: 73394 14:58:01 mischat_ has joined #rdf-wg 14:58:08 AndyS1 has joined #rdf-wg 14:58:15 gavinc has joined #rdf-wg 14:58:28 +??P8 14:58:38 +Tony 14:58:38 AZ has joined #rdf-wg 14:58:48 +Sandro 14:58:58 Zakim, ??P8 is me 14:58:58 +SteveH; got it 14:59:05 +??P7 14:59:18 zakim, ??P7 is me 14:59:18 +mischat_; got it 14:59:20 Zakim Tony is me 14:59:22 hello all 14:59:25 zakim, code? 14:59:25 the conference code is 73394 (tel:+1.617.761.6200 tel:+33.4.26.46.79.03 tel:+44.203.318.0479), gavinc 14:59:51 +AxelPolleres 14:59:57 +[IPcaller] 14:59:58 +[IPcaller.a] 15:00:09 Zakim, who is here? 15:00:09 On the phone I see davidwood, SteveH, Tony, Sandro, mischat_, AxelPolleres, [IPcaller.a], [IPcaller] 15:00:11 +??P15 15:00:13 zakim, IPcaller.a is me 15:00:13 +AndyS; got it 15:00:14 +gavinc 15:00:17 zakim, IPCaller is me 15:00:17 +mbrunati; got it 15:00:20 (probably) 15:00:33 Zakim Tony is Scott 15:00:49 +OlivierCorby 15:00:51 +Luca 15:01:03 zakim, Tony is Scott 15:01:03 +Scott; got it 15:01:11 zakim, Luca may be me 15:01:11 +AZ?; got it 15:01:19 AlexHall has joined #rdf-wg 15:01:39 zakim, what's the coe? 15:01:39 I don't understand your question, cygri. 15:01:44 zakim, what's the code? 15:01:44 the conference code is 73394 (tel:+1.617.761.6200 tel:+33.4.26.46.79.03 tel:+44.203.318.0479), cygri 15:01:59 +AlexHall 15:02:07 zakim, dial ivan-voip 15:02:07 ok, ivan; the call is being made 15:02:09 +Ivan 15:02:09 +mhausenblas 15:02:23 FabGandon has joined #rdf-wg 15:02:24 zakim, mhausenblas is temporarily me 15:02:24 +cygri; got it 15:02:29 + +34.67.92.aaaa 15:02:36 appologies, I can't make this meeting 15:02:47 +??P21 15:02:56 Zakim, i am ??P21 15:02:57 +webr3; got it 15:03:11 zakim, i am +34.67.92.aaaa 15:03:13 +JFB; got it 15:03:40 zwu2 has joined #rdf-wg 15:03:55 zakim, mute me 15:03:55 JFB should now be muted 15:03:58 +LeeF 15:04:12 agenda: http://www.w3.org/2011/rdf-wg/wiki/Meetings:Telecon2011.04.20 15:04:16 PatH has joined #rdf-wg 15:04:16 +zwu2 15:04:23 zakim, mute me 15:04:23 zwu2 should now be muted 15:04:33 Scribe: Olivier Corby 15:04:45 ScribeNick: OlivierCorby 15:04:49 + +20598aabb 15:04:57 zakim, aabb is danbri 15:04:57 +danbri; got it 15:05:09 AxelPolleres LOL 15:05:15 +Souri 15:05:24 Souri has joined #rdf-wg 15:05:50 +tomayac 15:06:00 PROPOSED to accept the minutes of the FTF1: 15:06:00 http://www.w3.org/2011/rdf-wg/meeting/2011-04-13 15:06:00 http://www.w3.org/2011/rdf-wg/meeting/2011-04-14 15:06:21 there is an issue 15:06:31 i haven't cleaned up my scribed session, I will definitely get round to that soon 15:06:34 note in the minutes 15:06:54 +[Sophia] 15:06:56 two people would vote -1 15:07:01 That doesn't seem like an issue with the minutes 15:07:26 (can the dissent be linked from the issue tracker as a hub?) 15:07:41 zakim, [Sophia] is me 15:07:41 +FabGandon; got it 15:07:46 Thanks very much to the scribes from F2F -- minutes are very helpful 15:07:52 one of the -1's was mine I know that 15:08:27 LeeF: +1 15:09:00 this email is part of the thread: http://lists.w3.org/Archives/Public/public-rdf-wg/2011Apr/0360.html 15:09:09 link: http://lists.w3.org/Archives/Public/public-rdf-wg/2011Apr/0310.html 15:09:25 antoine.zimmermann@deri.org 15:09:29 yes I did vote -1 15:09:33 http://www.w3.org/Search/Mail/Public/search?type-index=public-rdf-wg&index-type=t&keywords=-1&search=Search 15:09:55 +PatH 15:10:01 +OpenLink_Software 15:10:01 put the URLs in the minutes 15:10:19 Zakim, OpenLink_Software is temporarily me 15:10:19 +MacTed; got it 15:10:22 Zakim, mute me 15:10:22 MacTed should now be muted 15:11:15 actions under review 15:11:26 davidwood, AZ: http://lists.w3.org/Archives/Public/public-rdf-wg/2011Apr/0307.html 15:11:35 action 20 15:11:35 Sorry, bad ACTION syntax 15:11:40 http://www.w3.org/2011/rdf-wg/track/actions/20 15:12:21 http://www.w3.org/2011/rdf-wg/wiki/JSON_Syntax_Options 15:12:25 it looks ok to me ^^ 15:12:43 we can close the opening. 15:12:59 link correction: http://www.w3.org/2011/rdf-wg/wiki/JSON-Serialization-Examples 15:13:10 sorry tomayac 15:13:22 yours was webr3's great work 15:14:00 davidwood, and here's the -1 from webr3: http://lists.w3.org/Archives/Public/public-rdf-wg/2011Apr/0310.html 15:14:13 ACTION-27: Make sure the resolution to issue-12 gets into semantics document 15:14:14 ACTION-27 Make sure the resolution to issue-12 gets into semantics document notes added 15:14:48 27 and 28 are duplicated 15:16:33 OlivierCorby, please try to put the name or nick of the speaker first, like this: 15:16:47 "davidwood: action-123 is done" 15:17:10 wiki-ize? 15:17:11 action 123?? 15:17:11 Sorry, bad ACTION syntax 15:17:19 OlivierCorby, feel free to interrupt us if you want to ask who's speaking 15:17:58 PatH, sorry was just trying to give an example to the scribe 15:18:18 I had this vision of a *very* long action list... 15:19:17 Poll for F2F2 15:19:23 Review the poll regarding location/dates and results: 15:19:23 http://www.w3.org/2002/09/wbs/46168/RDFWGFTF2/ 15:19:23 http://www.w3.org/2002/09/wbs/46168/RDFWGFTF2/results 15:19:56 19 people not responding 15:20:30 -Ivan 15:20:35 towards east cost early october 15:21:06 please respond to the poll 15:21:24 Just realized a conflict, can I change my vote? 15:21:40 Please indicate attendance at: http://www.w3.org/2011/rdf-wg/wiki/F2F2 15:21:41 wiki page for F2F 2 & 3 15:21:44 yes. zwu2 15:21:48 Yes, just resubmit the form 15:21:51 Would there be an option to do a two site F2F with a European site connected via Video conf.? 15:21:55 thanks Sandro 15:22:02 +1 to Axel 15:22:07 AxelPolleres, +1 15:22:09 q+ 15:22:13 +1 to Axel 15:22:19 Graph task force 15:22:39 AZ has joined #rdf-wg 15:23:02 ivan has joined #rdf-wg 15:23:30 zakim, dial ivan-voip 15:23:30 ok, ivan; the call is being made 15:23:31 +Ivan 15:23:36 east coast US works well re: time difference 15:23:45 q+ 15:23:51 remote participation is possible ? 15:24:10 That room at MIT is cozy :) 15:24:27 try with skype 15:24:43 I was impressed by how well the remote participation worked in the last F2F. Dont think that full video is really nfecessary. 15:24:44 The nice thing about the 2-site F2F is that having multiple people at each site helps keep everyone more focused 15:24:50 Skype is flaky. 15:24:59 +! to ivan, skype not always reliable... 15:25:05 bad experience with skype 15:25:09 +1 to ivan. 15:25:24 AndyS ++ 15:25:35 +1 to Andy 15:25:48 AndyS++ 15:26:09 q? 15:26:13 q+ 15:26:27 Zakim, who is speaking? 15:26:37 ack AxerPolleres 15:26:38 davidwood, listening for 10 seconds I heard sound from the following: davidwood (33%), AxelPolleres (29%), PatH (14%) 15:26:41 2-site F2F is very good (east coast 8-5pm is tolerable for western Europe time zone, but it does not work the other way :-)) 15:26:45 Everyone in the SPARQL group loved the 2-site, video-linked, F2F style. 15:26:47 zakim, unmute me 15:26:47 zwu2 should no longer be muted 15:26:49 ack zwu 15:26:51 Remote to the F2F1 as fine, other then time zone ;) 15:26:57 ack AxelPolleres 15:26:58 zakim, ack me 15:26:59 I see AndyS on the speaker queue 15:27:50 ack AndyS 15:27:50 zakim, mute me 15:27:51 zwu2 should now be muted 15:27:55 Poll still open, can change vote 15:28:31 Site in Europe ? 15:29:33 mischat, good thought. 15:29:51 i could ask ECS, and I could ask W3C UK offices 15:29:55 and will report back 15:29:59 yes 15:30:04 mischat, ECS has the wrong system 15:30:16 but yes they have video geeks ... 15:30:19 action: mischat look into soton video conf facilities 15:30:19 Created ACTION-40 - Look into soton video conf facilities [on Mischa Tuffield - due 2011-04-27]. 15:30:20 will ask anyways 15:30:40 zakim, who is making noise ? 15:30:43 AZ has joined #rdf-wg 15:30:49 Skolemization 15:30:51 mischat, listening for 10 seconds I heard sound from the following: Sandro (60%), gavinc (15%), davidwood (53%) 15:30:57 Topic: Skolemization 15:31:05 Sandro proposal from F2F 15:31:26 discussion on this 15:31:37 move on resolution ? 15:31:43 pfps has joined #rdf-wg 15:31:46 SteveH: 15:31:49 http://lists.w3.org/Archives/Public/public-rdf-wg/2011Apr/0357.html 15:31:53 Steve's Proposal: 15:31:53 Systems wishing to skolemise bNodes, and expose those skolem constants to external systems (e.g. in query results) SHOULD mint fresh a "fresh" (globally unique) URI for each bNode. 15:31:53 All systems performing skolemisation SHOULD do so in a way that they can recognise the constants once skolemised, and map back to the source bNodes where possible. 15:31:53 Systems which want their skolem constants to be identifiable by other systems SHOULD use the .well-known URI prefix. 15:33:02 using a scheme to detect is it a bnode 15:33:09 SteveH: yves strongly opposed SHOULD requirement to .well-known 15:33:40 +q 15:33:43 SteveH: tried to come up with careful wording to allow use cases 15:34:00 slightly happier about this wording, although still concerned with possible over-complexity and mis-interpretations 15:34:14 q+ 15:34:36 ack PatH 15:34:58 SteveH: having a URI that claims to be a bnode somewhere in the URI is nonsense 15:35:18 PatH: we should not publish anything that discourages use of blank nodes 15:35:50 that seems incorrect, cygri... "we should not publish anything that discourages use of blank nodes" is not what I heard 15:35:51 pat: the only case that matters is where the publisher wants others to know that some of the URIs are special, that there is no other info to be had about this thing. 15:36:19 MacTed then please correct it 15:36:23 q+ to note the "But I didn't say that..." scenario; we shouldn't put URIs "into other's mouths" 15:36:28 steve: it matters for your own system to be able to recognize what was a bnode, but other systems dont need to be able to tell. 15:36:30 So should it be kosher for a graph store to consume something like _:b :loves :Mary and then emit something like :Mary :loves :Mary (and consider these two to be somehow close in meaning)? 15:36:34 q- 15:36:39 pat: in that case, why do we need a standard here? 15:36:58 PatH: we should not publish anything that discourages replacement of blank nodes with URIs of whatever coinage 15:37:06 cygri ^^^^^ 15:37:15 (is what I get from his words...) 15:37:59 I think it is worth the WG mentioning as folks keep inventing it on their own 15:38:05 steve: consequences to sparql update: if you skolemize at export time, then you have to be able to recognize uris coming in as those, so you can unify them with the bnodes in your store. 15:38:14 and that's (yet another) reason to avoid bnodes 15:39:01 pat: we're defining a spec about publishing content. what you're talking about is a private matter. 15:39:03 q+ 15:39:23 steve: sure, it doesn't add something, but it's worth pointing out. 15:39:34 perhaps for the primer ? 15:39:45 andy: I like it as a practical experience note. 15:40:03 q+ 15:40:12 I guess Im worried that if we talk about "skolemization" and use SHOULD language, what we write gets to be holy writ. 15:40:30 ack danbri 15:40:30 danbri, you wanted to note the "But I didn't say that..." scenario; we shouldn't put URIs "into other's mouths" 15:40:46 NICE. 15:40:55 +1 danbri for this usecase 15:41:35 danbri: if I take a graph from someone, skolemize, and republish, it's nice to be able to be clear that you've done this. 15:41:53 -Ivan 15:41:59 danbri: yes, but that issue is, who is responsible for the 'new' URIs. And the rule surely is, whoevewr coins the URis is responsible for them. 15:42:06 ack sandro 15:42:22 ivan, we lost you in audio? 15:42:27 I dont think danbri's case is a use case. 15:42:41 it's a mis-use case 15:42:46 :-) 15:43:01 +q 15:43:02 dan loads pat's graph, does some trivial transform, republishes it, sandro consumes it, and wants to know what pat actually said 15:43:19 q+ 15:43:20 (much as we might care to avoid muddle if dan retransmitted pat's sayings via rdf'99 reification?) 15:43:23 Why is SHOULD considered holy writ? Surely MUST is... 15:43:30 Zakim, unmute me 15:43:30 MacTed should no longer be muted 15:43:32 q? 15:43:32 q+ 15:43:39 ack PatH 15:43:40 problem with multigraph that may share bnodes 15:44:51 q+ 15:45:03 My action-27 cannot be done until issue-12 is closed, so I've extended the due date for a while. 15:45:34 q+ 15:46:06 ack SteveH 15:46:13 pat: what about just saying the one who mints an IRI is responsible for it? 15:46:27 sandro: yeah, that could work. 15:46:41 if people are talking about a specific something by name, then what is the difference between that and a uri-ref, as soon as anybody skolemizes and somebody else uses that uri, then people are talking about a specific thing rather than just something, surely? 15:46:50 ivan_ has joined #rdf-wg 15:46:53 +1 to speaker. 15:46:56 why does it need to be globally unique? 15:46:57 steve: I don't want to throw the baby out with the bathwater. Skolemizing is what the vast majority of stores now, and I don't like everyone ignoring the standard. 15:47:03 Umm, what is the standard specifying?? 15:47:16 ... that is being ignored? 15:47:16 q? 15:47:20 zakim, dial ivan-voip 15:47:20 ok, ivan_; the call is being made 15:47:22 +Ivan 15:47:27 q? 15:47:57 steve: "systems that issues URIs are responsible for them" 15:48:18 steve: I just think it makes sense to codify the common practice. 15:48:26 pfps, that a blank node label is not valid outside the scope of the graph in which it appears? 15:48:28 q- 15:49:06 david: Steve, can you write a new proposal that attempts to capture that? 15:49:09 re responsibility, yeah i tihnk that's part of the issue 15:49:46 AlexHall, but there's no way you can prevent people from using that uri in another doc? 15:49:47 steve: "if you want your URIs to be identified as sk bno then you should..." is what Pat doesn't like 15:49:47 so if i ascribe to pat as author of a graph, but am actually pointing at a graph full of skolem'd bnodes i interfered with, ... is that misrepresenting pat? 15:49:58 I think that I would be unhappy. 15:50:00 ack MacTed 15:50:14 q- 15:50:51 consistent?? 15:51:06 q+ to suggest we have a theory vs practice argument 15:51:07 q+ 15:51:37 For practical purposes, systems might wish to replace blank nodes by URIs. If done, the responsibility for the meaning of these newly introduced URIs lies with the publisher of the modified data. 15:51:53 ted: bnodes are nothing but trouble 15:52:06 sandro: this group isn't saying anything of the sort 15:52:17 minting open-ended descriptive promises to the planet - also can be troubling 15:52:20 Can we have the wording for any proposal (= evolving working draft) on the wiki please - easier to point to at resolution. It took me some time (error prone?) creating a single, consolidated view. 15:52:34 q+ 15:52:48 Whoa. this is not to do woth names being 'variable'. 15:53:02 +1 AndyS -- we need a stable on-wiki wording for any proposal 15:53:14 ack Souri 15:53:23 q- 15:53:24 q- 15:53:41 Cant draft text and listen at the same time. 15:53:47 Souri: bnodes are nothing but local-scope variables. once you make it, it's not visible outside the scope. 15:55:10 Souri: let the externalizer map the bnode to a URI and then it's normal, and can be used outside. 15:55:11 souri: agreed. Our role as a WG is not to rule on private mappings used inside tools. Its only our business when it gets published. 15:55:38 proposal: http://www.w3.org/2011/rdf-wg/wiki/Skolemisation 15:55:41 Souri: ... and then provide a predicate to connect generated URI to the bnode. 15:55:44 souri just summarized the entire idea of skolemization, using programming terminology. 15:55:45 How about externalizing a bNode by specifying a mapping from bNode to a URI => _:b1 rdf:graphIRI . _:b1 rdf:bNode2IRI :someUriExternalizerChooses . (or we can use the owl:sameAs property, but that could be an overkill) 15:56:05 q+ 15:56:12 Exactly, it is up to the app. designer. NOt our business to een know about that. 15:56:14 fair to summarize as: skolemization should happen behind the interface before data hits the wire (so no bnodes show to the outside world)? 15:56:50 +1 webr3 15:57:01 It **is** skolemization. 15:57:06 ehhh, skeptical about rdf:bNode2IRI. wrong level. 15:58:16 Aaargh, don't say URI **represents** a bnode, please... 15:58:29 q- 15:58:30 +1 to separate what and how 15:58:34 PatH, if everybody did that, then there would be no bnodes on the wire, as in no bnodes in serializations or in "visible" rdf ? 15:58:40 ack cygri 15:58:53 If everybody did that, yes. BUt of course they wont ALL do it. 15:59:11 cygri, nooooo. 16:01:27 cygri: In practice you're often confronted with other people's bnodes -- by saying something about sk in our docs, ("look here's a process for when you get bnodes you didnt want...") ... I see Pat's point about it's your own private business, as long as you keep to your own URIs in the process, then why would anyone ned to know about it? I think, however, there is value in writing down the fact that it is okay to do so. It is NOT obvious. YOu have to s 16:01:27 pend a lot of time with RDF before you know that. 16:01:35 q? 16:01:39 other people skolemizing my data worries me, because for every person that does it the bnode is effectively forked, has multiple identifiers, which makes it impossible to manage, you can't merge or diff graphs fromt he same source, manage data over time etc - which completely invalidates the point of skolemizing afaict 16:02:03 webr3 - that's the reason for *you* to not use bnodes... 16:02:10 Zakim, mute me 16:02:11 MacTed, exactly 16:02:22 MacTed should now be muted 16:02:24 i don't think people get confused between whether to use a bnode or not. If you don't want your data to be dereferencable via a URI, you use a bnode ... 16:02:30 cygri: This doesn't speak to making the skolem constants reconginizable. But it's nice to have a simple recipe that avoids one having to think too much. 16:03:07 http://www.w3.org/2011/rdf-wg/wiki/Skolemisation 16:03:08 http://www.w3.org/2011/rdf-wg/wiki/Skolemisation 16:03:10 webr3, I think that managing over time is made tricky just by there being multiple copies. 16:03:38 q+ 16:03:43 q? 16:03:53 zakim, unmute me 16:03:54 q+ to suggest a use case: dan publishes a previously private graph. it has some bnodes / skolems representing objects that dan didn't know good public URIs for, and didn't host his own. Sandro loads up that document and reading the properties of the objects it describes, figures out some good replacement URIs. Because he can see which URIs are transient bnode-derrived skolem URIs, Sandro can now REPLACE those in the graph, rather than complicate 16:03:54 the graph with sameAs links to the 'better' well known URIs. 16:04:00 q+ 16:04:04 zwu2 should no longer be muted 16:04:10 Would like to say all this without using 'skolem' anywhere. DOn't need to revert to logic-jargon for the general reader. 16:04:16 in other words -- other people will skolemize (and here's a reasonable way to do that...), when they want to reuse data sets that came to them including bnodes. That causes problems down the line. So it's best not to use bnodes.... :-) 16:04:30 PatH, or just by having bnodes at all, it requires the ability to say "something, let us all call it X all the time" afaict 16:04:44 q? 16:04:47 ack Zhe 16:05:00 ack zwu 16:05:38 zwu2: I'm in favor of skolemizing, but isn't globally unique too strong? why not just locally unique to your store? globally unique is harder. 16:06:33 UUID solves this pretty well. 16:06:43 but then why not just use a URI 16:07:04 The skolem name has to be a URI. What does it mean to say that a URI is only locally unique? 16:07:08 urn:bnode:: 16:07:27 Federated Query too 16:07:42 +1 to gavinc 16:07:43 q+ 16:07:48 ack danbri 16:07:48 danbri, you wanted to suggest a use case: dan publishes a previously private graph. it has some bnodes / skolems representing objects that dan didn't know good public URIs for, and 16:07:51 ... didn't host his own. Sandro loads up that document and reading the properties of the objects it describes, figures out some good replacement URIs. Because he can see which URIs 16:07:56 ... are transient bnode-derrived skolem URIs, Sandro can now REPLACE those in the graph, rather than complicate 16:08:00 I think that the SHOULD should be a MUST for globally unique. 16:08:48 for reference, RFC 2119: SHOULD This word, or the adjective "RECOMMENDED", mean that there may exist valid reasons in particular circumstances to ignore a particular item, but the full implications must be understood and carefully weighed before choosing a different course. 16:09:26 Zakim, close the queue 16:09:27 ok, davidwood, the speaker queue is closed 16:09:31 What danbri is talking about might be called data quality improvement. I agree, people will do this, and its a good thing. But its not skolemization. 16:09:48 +1 danbri: the flagging might be useful because it lets you throw away the URIs, BUT there may well be other data that grows up using it, so maybe you can't throw it away. 16:10:06 yes, but I think that there is a big distinction between this SHOULD and later SHOULDs in the proposal 16:10:20 pfps, +1 16:11:13 q- 16:11:16 ack Souri 16:11:18 sandro, in data that's all bnodes, this is literally impossible 16:11:34 sandro: steve, I agree the sparql-loop is useful but I don't think it's compelling, since users can just write a better query. 16:11:36 AZ has joined #rdf-wg 16:11:39