13:57:18 RRSAgent has joined #shapes 13:57:18 logging to http://www.w3.org/2015/02/19-shapes-irc 13:57:20 RRSAgent, make logs rdf-data-shapes 13:57:20 Zakim has joined #shapes 13:57:22 Zakim, this will be SHAPES 13:57:23 Meeting: RDF Data Shapes Working Group Teleconference 13:57:23 Date: 19 February 2015 13:57:24 ok, trackbot; I see DATA_RDFWG()8:00AM scheduled to start 57 minutes ago 13:57:48 pfps has joined #shapes 13:57:54 zakim, code? 13:57:54 the conference code is 742737 (tel:+1.617.761.6200 sip:zakim@voip.w3.org), Arnaud 13:57:59 pfps has changed the topic to: https://www.w3.org/2014/data-shapes/wiki/F2F2#Day_3_-_Thursday_February_19 13:58:39 DATA_RDFWG()8:00AM has now started 13:58:46 +pfps 13:58:48 + +1.617.715.aaaa 14:00:05 zakim, aaaa is F2F 14:00:05 +F2F; got it 14:01:08 + +30694579aabb 14:01:23 zakim, +30694579aabb is me 14:01:23 +Dimitris; got it 14:02:34 kcoyle has joined #shapes 14:04:53 +??P14 14:05:03 zakim, ??P14 is me 14:05:03 +SimonSteyskal; got it 14:06:41 zakim, F2F has ericP, ArthurRyman, iovka, labra, kcoyle, hsolbrig, tallted 14:06:41 +ericP, ArthurRyman, iovka, labra, kcoyle, hsolbrig, tallted; got it 14:07:07 scribe: pfps chair: Arnaud agenda: https://www.w3.org/2014/data-shapes/wiki/F2F2#Day_3_-_Thursday_February_19 14:07:35 topic: Agenda 14:07:49 Arnaud: next F2F, remaining requirements 14:08:56 Arnaud: also high-level issues 14:09:02 topic: Next F2F 14:09:46 Arnaud: F2F meetings are important because of the concentration of effort 14:09:53 WU Vienna would be happy to host the next F2F. There is the SEMANTiCS Conference at WU on September 15th-17th so we could maybe schedule it around that date.. 14:10:16 (or earlier) 14:10:36 Arnaud: three months from now is May 14:11:09 hsolbrig has joined #shapes 14:11:15 Arnaud: there is a W3C meeting in Paris in May, ESWC in Slovenia in June, WWW in Florence in May 14:11:30 labra has joined #shapes 14:12:12 Arnaud: having a host helps a lot - it's not much money to be a host 14:12:48 Arnaud: it is not necessary to be co-located with something, but it can help 14:13:15 ??: Lille can probably host 14:13:23 +q 14:13:32 Arnaud: we don't need to confirm just now 14:13:33 s/??/iovka/ 14:13:40 ack SimonSteyskal 14:13:57 Simon: Vienna can host, just about any time 14:14:26 Arnaud: is anyone going to any of the mentined events 14:14:45 I may be going to ESWC and/or DL, which is just after ESWC 14:15:43 Arnaud: Americans don't want to go to Europe 14:16:01 Arnaud: organizations don't want to pay 14:16:29 *I 'll be in a project meeting at 25/5-29/5 * 14:18:02 ArthurRyman has joined #shapes 14:18:12 Participation See list of current participants, (or with contact info), wiki user pages, nicknames. 14:19:06 iovka has joined #shapes 14:19:08 zakim, who's on phone? 14:19:08 I don't understand your question, Arnaud. 14:19:23 s/Participation See list of current participants, (or with contact info), wiki user pages, nicknames. // 14:19:52 zakim, who's on the phone? 14:19:52 On the phone I see pfps, F2F, Dimitris, SimonSteyskal 14:19:53 F2F has ericP, ArthurRyman, iovka, labra, kcoyle, hsolbrig, tallted 14:19:59 I think that Nuance could host in Montreal or Waterloo just about any time over the summer 14:21:00 TallTed has joined #shapes 14:21:49 cygri has joined #shapes 14:22:05 +??P24 14:22:09 zakim, ??P24 is me 14:22:09 +cygri; got it 14:22:11 zakim, mute me 14:22:11 cygri should now be muted 14:24:02 Arthur: IBM could host in Toronto 14:24:27 ack me 14:25:19 zakim, mute me 14:25:19 cygri should now be muted 14:25:22 cygri: I don't know whether TQ can host in Raleigh 14:25:27 iovka_ has joined #shapes 14:26:04 boneva has joined #shapes 14:26:14 Arnaud: F2F in May in NA? 14:26:36 Arnaud: A European meeting could be the next one (September?) 14:26:53 iovka_ has joined #shapes 14:27:28 iovka_ has joined #shapes 14:29:17 *I will not be available in the last week of May* 14:31:18 Arnaud: May 19-21 in Toronto? 14:33:03 Ted can't make that week or early the next week 14:33:30 Arnaud: May 27-29 in NA? 14:34:19 ACTION: cygri to check TQ F2F availability on May 19-21 or 27-29 14:34:19 Created ACTION-13 - Check tq f2f availability on may 19-21 or 27-29 [on Richard Cyganiak - due 2015-02-26]. 14:34:24 Arnaud: participants should determine their availability these two weeks, potential hosts should determine whether they can host 14:34:56 topic: Requirements 14:35:28 Arnaud: I worked on the requirements page to make it match the discussion of two days ago 14:36:33 Arnaud: Property Datatype? 14:36:45 pfps: still waiting for semantic media wiki 14:37:34 karen: what's the change 14:37:48 *make a sub-heading* 14:37:48 pfps: it's whether int is an integer or not 14:38:21 ACTION: pfps fix up Property Datatype in a way that doesn't confuse the wiki 14:38:21 Created ACTION-14 - Fix up property datatype in a way that doesn't confuse the wiki [on Peter Patel-Schneider - due 2015-02-26]. 14:38:29 https://www.w3.org/2014/data-shapes/wiki/Requirements#Datatype_Property_Facets 14:38:46 Arnaud: Datatype Property Facets 14:39:17 Arthur: facets are things like the maximum length of a string 14:39:54 Arnaud: there is little support for this in the wiki 14:40:03 q+ 14:40:06 I should have voted as well 14:40:21 ack pfps 14:40:51 isn't this just defining a shape for this property? 14:41:11 pfps: voting on the spot makes it hard to respond 14:41:51 eric: my objection is that I want to consider different facets separately 14:42:06 q+ 14:42:21 eric: if this is just the notion of facets, then sure 14:42:37 ack hsolbrig 14:43:11 harold: it this strictly for forms? 14:43:32 arthur: no, these are validation-related 14:44:21 arnaud: If people want this they should vote or make additions 14:45:19 dimitris: how about the XML Schema facets? 14:45:29 all mentioned examples can easily be written as a SPARQL expression (like used in FILTER) 14:45:54 ack me 14:46:07 pfps: OWL has vocabulary for many of the XML Schema facets 14:46:15 s/dimitris/labra/ 14:46:41 richard: all the mentioned ones are SPARQL filters 14:47:02 zakim, mute me 14:47:02 cygri should now be muted 14:47:18 the OSLC submission contains a proposal for facets: http://www.w3.org/Submission/2014/SUBM-shapes-20140211/#datatype-facets 14:47:21 we have quite a few use cases which require this feature so.. 14:47:55 Arnaud: we should have been following the approved process, i.e., only look at ones that are under consideration 14:48:13 https://www.w3.org/2014/data-shapes/wiki/Requirements#Expressivity:_Aggregations 14:48:24 I believe all XSD facets except whitespace can be handled by vanilla SPARQL expressions. 14:48:26 Arnaud: Expressivity: Aggregations 14:48:45 *ericP, jimkont* 14:48:49 this has 2.5 votes 14:49:12 I like it 14:49:19 Arnaud: there are objections - does anyone arguing for it? 14:49:33 ack me 14:50:14 Richard: aggregations can be useful, but there is the consideration of expense 14:50:24 zakim, mute me 14:50:24 cygri should now be muted 14:50:46 q+ to ask if our requirements are for the core vocabulary or extensions 14:51:07 ack ericP 14:51:07 ericP, you wanted to ask if our requirements are for the core vocabulary or extensions 14:51:32 ack me 14:51:48 Eric: some of these can be solved as SPARQL so are these things that have to be done outside of directly using SPARQL? 14:51:55 q+ 14:52:35 Eric: let's also vote whether we need vocabulary for these 14:52:37 q+ 14:52:38 ack cygri 14:53:07 Richard: I'm not sure that we have resolved that SPARQL is not needed 14:54:13 +q 14:54:18 Richard: i.e., is there a profile that does not include SPARQL? 14:54:35 Richard: the core vocabulary is only for convenience 14:54:35 ack pfps 14:54:40 zakim, mute me 14:54:40 cygri should now be muted 14:55:21 q+ to say that i'd still like to vote on what's in the core vocabulary 14:55:25 pfps: Is SPARQL the extension language? 14:55:48 I’d like SPARQL to be *the* language, and then there’s syntactic sugar. 14:56:14 pfps: i haven't heard that the division is on the core vocab vs. SPARQL extensions 14:56:30 ... lots of talk about SPARQL being necessary, good, or not evil 14:56:50 ... but nothing saying that there's a core and SPARQL which is the extension 14:58:33 ack labra 14:58:40 Arnaud: there has been as of yet no division into a core language and SPARQL as the extension language 14:59:21 jose: we shouldn't mix the high-level language and SPARQL 14:59:21 ack ericP 14:59:21 ericP, you wanted to say that i'd still like to vote on what's in the core vocabulary 14:59:47 q+ 15:00:06 ack me 15:00:19 eric: we are defining a vocabulary and functionality of it - is voting for minlength voting for this vocabulary and functionality in the core? 15:00:20 ack cygri 15:01:52 richard: eric moved SPARQL stuff out of the primer which makes me think that the ability to do arbitrary SPARQL queries is not in the core language 15:02:12 http://www.w3.org/2014/data-shapes/charter#deliverables 15:02:21 richard: taking SPARQL out of the core changes a lot of thinking about expressivity 15:02:25 a litmus for whether SPARQL is part of the core is whether someone can have a conformant implementation without a SPARQL engine 15:02:57 Arnaud: the charter calls out some expressivity plus some extensibility 15:03:22 Arnaud: that is the minimum, we could do more 15:03:53 ack me 15:04:26 eric: are we clear on whether voting is for inclusion in the core, without this I'm unclear as to how to vote 15:05:49 richard: in LDOM there are templates, so all the core stuff can be a macro library 15:06:11 eric: does it matter to you what is the core language? 15:06:38 richard: not much, because I can just write a macro 15:07:10 Arnaud: is there a requirement for an extension mechanism? 15:08:08 Arnaud: what would an extension mechanism be? should we just have a procedural call-out? should we specify a particular mechanism (like SPARQL)? 15:08:55 Arnaud: in HTML there is a standard mechanism to attach a style sheet, but it doesn't have to be CSS; similarly for scripting, which doesn't have to be javascript 15:09:14 +q 15:09:25 ack hsolbrig 15:10:07 harold: it may be hard to test such extension mechanisms 15:10:54 ack me 15:11:00 eric: can we state which requirements are in the core? 15:12:33 richard: there is a requirement for macros, but do macros look like the other parts of the language? 15:13:02 richard: if macros don't look like the core then it becomes more important to determine the boundaries of the core 15:13:11 eric: the namespace would be different 15:13:19 richard: is this the only difference 15:13:34 *Thank you EricP* 15:13:45 richard: or is invoking macros syntactically difficult 15:15:02 eric: even if there is little difference the division is needed 15:15:03 q+ 15:15:45 richard: if the macro facility is powerful then the core can be empty 15:16:40 q+ 15:16:45 richard: it is more important to get the macro facility set up 15:16:47 ack pfps 15:16:55 zakim, mute me 15:16:55 cygri should now be muted 15:17:26 pfps: in latex, there's no significant difference between macros and core language facilities 15:17:30 ack iovka_ 15:17:35 pfps: reiterate richard's comment 15:17:41 ... so if the macro facility is like that, then who cares? 15:18:04 iovka: I want to be able to perform analysis on the core language 15:18:25 https://www.w3.org/2014/data-shapes/wiki/Requirements#Separation_of_structural_from_complex_constraints 15:18:39 Arnaud: there is supposed to be a separation between structural and complex constraints 15:19:03 https://www.w3.org/2014/data-shapes/wiki/Requirements#Expressivity:_Closed_Shapes 15:19:09 Arnaud: Closed Shapes 15:20:26 eric: a use case is determining whether all triples in a graph can be moved over into something that can't handle arbitrary information 15:20:42 q+ 15:20:42 eric - can you add that to the requirement description? 15:20:45 q+ 15:21:06 eric: people also just want to say "that's all folks!" 15:21:40 eric: closed shapes can also mediate into applications 15:21:41 q+ 15:21:47 ack ArthurRyman 15:21:49 q+ 15:22:23 Arthur: one use case for shapes was to advertise what can be generated 15:23:03 Arthur: if there is other stuff then a server could throw away what doesn't match 15:23:21 Arthur: closed shapes appears to be different as it signals a violation 15:24:03 eric: but closed shapes is needed to make the determination 15:24:12 ack me 15:25:27 an OSLC Shape serves to document the "known" or "expected" content - this is content that the service will do something useful with 15:25:53 richard: shape coverage is a related notion, and might be what eric needs 15:26:21 an OSLC service should not reject requests that contain unknown content, but it should provide an informative message in the HTTP response 15:26:37 +q 15:26:42 zakim, mute me 15:26:42 cygri should now be muted 15:26:56 q+ 15:27:37 ack TallTed 15:28:34 ted: shapes are all about limiting what is said, so the general "say anything about anything" matra does not apply 15:29:09 ack pfps 15:29:28 ted: severs should feel free to reject stuff that they don't want 15:29:46 pfps: my objection was the philosophical one 15:29:59 ... but the other is that someone has to come up with a definition for this 15:30:04 pfps: someone has to come up with a definition for this 15:30:09 ack labra 15:30:27 ... i don't understand what it's supposed to be or do, so i can't spec this 15:30:29 jose: i have a definition in the glossary 15:30:48 q? 15:31:08 q+ to say that use cases for mixed closed/and open shapes appear to be rare 15:31:10 jose: it should not be required for shapes to be closed 15:31:26 can links to glossary definitions be included in UC/Reqs/etc? we have tools that handle links. treating their content as literals is unfortunate. 15:31:31 q+ 15:31:42 q+ 15:31:46 ack ericP 15:31:46 ericP, you wanted to say that use cases for mixed closed/and open shapes appear to be rare 15:31:56 eric: use cases for mixed closed/and open shapes appear to be rare 15:32:25 jose's definition of a closed shape is something completely different from this requirement 15:32:41 ack iovka_ 15:32:43 “closed shape = 15:32:47 jose's definition of a closed shape is one that lives happily with open shapes 15:33:05 iovka: initially all shapes were closed 15:33:27 iovka's definition of a closed shape is like jose's 15:33:47 iovka: closed shapes are about the neighbourhodd 15:33:54 q+ 15:33:55 q+ 15:34:01 ack pfps 15:34:16 pfps: there are two very different definitions of closed shapes 15:34:20 ack ArthurRyman 15:34:58 the paper I was talking about http://www.grappa.univ-lille3.fr/~staworko/papers/staworko-icdt15a.pdf 15:35:00 arthur: closed shapes considered harmful because services and clients change 15:35:15 +1 to arthur 15:35:26 arthur: the open content model is a very desirable ideal 15:35:36 q+ 15:35:38 q- 15:36:16 Arthur: there needs to be movement on this before it can be approved 15:36:18 ack me 15:36:46 richard: how can I put forward the notion of coverage? 15:36:51 zakim, mute me 15:36:51 cygri should now be muted 15:37:12 ok, thanks 15:37:25 q+ 15:37:30 Arthur: if there is a story to support it, then start with the story; else start with a story 15:38:11 ack labra 15:38:22 jose: the portals user story might support coverage 15:38:41 thanks, labra 15:39:15 Arnaud: 10 minute break 15:39:18 labra: What I said is that a user story could be the "validating and describing" linked data portals 15:39:53 labra: where you want to describe the contents of a data portal and you want to say that you only allow a fixed number of triples 15:39:54 -Dimitris 15:40:48 labra: Previously, I had said that in my opinion, closed shapes should be a construct of the language, but they could be optional...by default we can have open shapes, and have some construct to define open shapes 15:53:29 ok 15:53:35 scribe: cygri 15:54:16 Topic: Requirements cont’d 15:54:56 https://www.w3.org/2014/data-shapes/wiki/Requirements#Severity_Levels 15:55:02 Arnaud: Next: Severity levels 15:55:17 … Objections from ericP and labra 15:56:22 ericP: We can do without. 15:57:28 kcoyle: The intention is that one non-match could be a fatal error and another non-match could just be informational 15:58:02 ... Matching is not just yes/no; I’d like to have different severities of no 15:58:55 q+ 15:59:02 ... Something a server might just want to reply, if you changed this then I could do more with your data 15:59:59 ... Anything that you’re testing for in your shape, you want to attach a level 16:00:39 Arnaud: The question is, what’s the granularity 16:01:35 ericP: So do you want to attach it to the property, or to a particular facet on that property such as cardinality or string length? 16:01:36 If you care about the distinction you can just have several shapes. 16:01:40 q+ 16:02:02 ack ArthurRyman 16:02:19 kcoyle: We want to return a message with a failure. That’s the needed granularity. 16:02:41 ArthurRyman: Attach comments/messages/severity to constraints 16:02:46 zakim, code? 16:02:46 the conference code is 742737 (tel:+1.617.761.6200 sip:zakim@voip.w3.org), Dimitris 16:03:10 ... deprecation as example; tolerate people using it, but want to include a message that says, use this other one 16:03:12 +Dimitris 16:03:15 ack pfps 16:03:45 pfps: If you want part of the shape to be warning and other very fatal, create two shapes, and tag one as this and the other as that 16:04:22 q+ 16:04:34 Arnaud: So that would mean, granularity is the shape 16:05:13 ArthurRyman: There can be cases where you have “growing” shapes, there’s something strictly required, then more stuff that’s just gloss 16:05:16 iovka has joined #shapes 16:05:28 q+ 16:06:07 Arnaud: If you reject this requirement, you don’t have a way of doing it at all 16:06:25 ericP: Well we wouldn’t get interop on severity levels, it can still be done outside the spec 16:06:28 ack labra 16:07:27 labra: My objection was to the way the requirement is written. It could be done as metainformation on the shape level. 16:07:37 ... But the validator should still be yes or no 16:08:24 ... I wouldn’t object to put this as metainformation on the shape, as structured information 16:09:01 ericP: I’d be happy with that. My concern is only that doing it at facet granularity would require reifying the facets. 16:09:16 ack Dimitris 16:09:28 labra: If there’s a way to add metainformation, anyone could define their levels 16:10:16 Dimitris: We do this in RDFUnit. We have severity levels on shape granularity and property granularity and you can select a level at execution time. Constraints at lower levels are skipped in validation. 16:10:34 ericP: In C terms, this is like IFDEF? 16:10:36 Dimitris: Yes. 16:11:03 ... Property granularity is useful 16:11:51 ericP: I could withdraw my objection. Not sure yet what the impact on complexity is. 16:12:14 Arnaud: There are different possible approaches. Let’s not get hung up on these details yet. 16:12:35 labra: I don’t object then. 16:12:53 kcoyle: I’m rewording the requirement. 16:13:09 The language should allow the creation of error responses that can include severity levels as desired 16:14:12 pfps: This wording pulls in the next requirement, about human-readable error messages 16:14:19 PROPOSED: Change description to: The language should allow the creation of error responses that can include severity levels as desired 16:14:29 +1 16:14:32 +1 16:14:34 +1 16:14:40 +1 16:14:41 +1 16:14:41 +1 16:14:41 +1 16:14:44 +0 16:14:45 +1 16:14:51 +0 16:14:52 +1 16:14:57 RESOLVED: Change description to: The language should allow the creation of error responses that can include severity levels as desired 16:15:21 +1 16:15:24 s/change description to:/change description of “Severity Levels” to:/ 16:15:55 PROPOSED: Approve 2.10.1 Severity Levels 16:16:12 RESOLVED: Approve 2.10.1 Severity Levels (hearing no objection) 16:16:40 https://www.w3.org/2014/data-shapes/wiki/Requirements#Human-readable_Violation_Messages 16:16:47 subtopic: Requirement “Human-readable Violation Messages” 16:17:17 Arnaud: Objections from labra and ericP 16:17:23 +q 16:17:53 ericP: This comes down to granularity again. This requires ability to add custom error messages at every facet. 16:18:33 ... So we’d need one text for violating minCardinality and another text for violating maxCardinality. This seems complex. 16:19:04 ... And if we simplify it by only allowing it at the property label, then we could solve it just by giving a label/comment to the property. 16:19:04 +q 16:19:13 q+ 16:19:32 ... To make this practical, you’d have to be able to provide custom error messages at the facet level of the property. 16:20:03 ack kcoyle 16:20:05 ArthurRyman: If your shape is at the facet level, that’s where your message goes. If your shape is at the property level, that’s where your mesage goes. 16:20:20 ericP: What would be a useful error message at a level higher than facet? 16:20:21 q+ 16:20:21 s/ArthurRyman/TallTed/ 16:20:56 kcoyle: This and the previous requirement go together. Indicate severity, and indicate message. 16:21:58 ack Dimitris 16:21:58 ... We have to discuss granularity first. 16:22:29 Dimitris: In RDFUnit we already have this, with separate messages at the facet level. 16:22:38 ... It was not hard to implement. 16:22:46 ack me 16:24:36 cygri: for clarification, these error messages are generated by the system? 16:25:12 ... in RDFUnit, the author can't customize the message, correct? 16:25:15 Dimitris: correct 16:25:29 cygri: kcoyle, are you content with system-generated? 16:25:39 kcoyle: i think they have to be customized 16:25:41 anywhere I may want a human-readable error message, I should also be able to assign an error level... and vice versa. 16:25:41 both should support multiple langs. 16:25:41 some built-in tests (e.g., max length) might have default messages in system -- but person defining shape should be able to provide custom error therein. 16:26:05 Dimitris: If the types of constraints are hardcoded, why are customised messages needed? 16:26:34 ack ArthurRyman 16:26:47 Arnaud: In the case of SPIN and LDOM, you have variables and so on, so it’s easier to customise 16:27:19 ArthurRyman: In the proposals where atomic constraints are not addressable, it’s hard to attach custom messages, you’d have to reify 16:27:33 ... But the system could generate good messages 16:27:49 ack labra 16:28:47 labra: Separate concerns. Validator should generate a data structure. Turning that into something human-readable is a later step and out of scope. 16:29:08 ... A report or data structure. 16:29:55 kcoyle: It needs to be specific to the test. Different shapes need different messages. As long as that can be done, it’s sufficient. 16:30:19 Arnaud: TallTed made the point that granularity for severity and messages should be the same 16:31:21 ... It’s useful if the system doesn’t just tell you, “You failed”, but “You failed because you have ten characters instead of five”. So the message must be dynamically assembled at runtime. This is more complicated, variable substitution, etc. 16:32:09 kcoyle: We need to get an idea of the granularity issue. 16:32:25 ericP: What would be practical messages that we’d like to customize? 16:32:49 kcoyle: Gather examples of actual errors people would like to report. 16:32:57 q+ 16:33:09 ack cygri 16:33:57 cygri: my impl of R2RML does complex validation of R2RML mappings 16:34:06 ... it uses a lot of custom error messages 16:34:27 ... i may be able to extract some examples of the sorts of error messages we'd like to automatically generate 16:34:59 *cygri, can you try RDFUnit on an R2RML doc?, we did some further work there* 16:35:38 ericP: I’d like to see examples and that might change my vote. 16:36:00 +q 16:36:15 q- 16:36:38