W3C

- DRAFT -

RDF Working Group Teleconference

29 Feb 2012

See also: IRC log

Attendees

Present
Regrets
Chair
SV_MEETING_CHAIR
Scribe
ericP

Contents


<trackbot> Date: 29 February 2012

<ivan> Zakim has a leap year bug… it does not recognize the 'this will be XXX' command. But if dialing in with the code, it will start (at least that is what our system guys told me…)

<AndyS> New UC --: <rdf-wg> :teleconDate [ :happendOn "2012-02-29"^^xsd:date ] .

<davidwood> PROPOSED to accept the minutes of the 22 Feb telecon:

<davidwood> http://www.w3.org/2011/rdf-wg/meeting/2012-02-15

<scribe> scribenick: ericP

<PatH> thanks eric

<davidwood> RESOLVED to accept the minutes of the 22 Feb telecon

<davidwood> Action item review:

<trackbot> Sorry, couldn't find user - item

<davidwood> http://www.w3.org/2011/rdf-wg/track/actions/pendingreview

<davidwood> http://www.w3.org/2011/rdf-wg/track/actions/open

antoine: ACTION-149 in progress
... will add references to related URLs

sandro: i think you should focus on the 5 use cases on @@1

<sandro> http://www.w3.org/2011/rdf-wg/wiki/Why_Graphs

antoine: i tried to focus on easy use cases listed as priority A on the use case page @@2

<AndyS> ?? Sandro says they are his personal choice ??

s/@@1/http://www.w3.org/2011/rdf-wg/wiki/Why_Graphs

s{@@1}{http://www.w3.org/2011/rdf-wg/wiki/Why_Graphs}

<sandro> AndyS, I just didnt want to presume anything from the WG at that point.

<davidwood> Close ACTION-148

<trackbot> ACTION-148 Write email about the "islands" idea closed

<davidwood> Close ACTION-141

<trackbot> ACTION-141 Propose a vocabulary and semantics for adding timestamps to RDF graphs closed

pat: re: ACITON-140, agree that only XSD 1.1 semantics implications are more valid forms, and that we refer to xsd:identity, not xsd:equality
... do we want to incorporate facets?

sandro: like from OWL2?

<AlexHall> I thought Pat's action was to review the WG note: http://www.w3.org/TR/swbp-xsch-datatypes/

<FabGandon> http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-xml/index.html

Turtle Escape Sequences

http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-turtle/index.html#sec-strings

<AndyS> Does not allow \u in strings?

<cygri> +1 to 4.4, it looks good

<sandro> cygri: Why not name the different escape mechanisms, then use those names when saying which kind is allowed where. eg "Local Name Escaping", etc.

<sandro> ... "Magic Special Character Escaping" is \t stuff. etc. Then say which you can do each place.

<sandro> +1 cygri

<sandro> ericP: Sounds reasonable.

<sandro> ... I'll present two options.

cygri: editorial proposal: name the escaping mechanisms and reference the names in e.g. IRI, local names, strings

<cygri> +1 sandro, to giving *some* explicit name to these escape mechanisms also makes talking about this stuff much easier

PROPOSAL: remove section 4.3 in <http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-turtle/index.html#sec-strings> and remove issue tag on 4.4

<sandro> sandro: if you can't come up with good names for the types, then just use type-1-escaping, type-2-escaping, etc. And have a table of which works where.

<sandro> +1

<ivan> +1

<AndyS> +1

<davidwood> +1

<cygri> +1

<MacTed> +1

+1

<PatH> +1

<zwu2> +1

<pchampin> +1

<pfps> +1

<Arnaud> +1

<yvesr> +1

<AlexHall> +1

<Souri> +1

http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-turtle/index.html#sec-escapes

<cygri> use both examples.

<pfps> +1 to previous proposal (dropped because my wireless dropped)

<pchampin> I too would keep both examples.

<sandro> sandro: Also, and say it's different from /Foo-bar

<sandro> davidwood: Good idea.

<sandro> ericP: Note is changed; I'll do the naming the different forms of escaping for tomorrow.

Named Graphs

PatH: do graph labels mean the same thing in different data sets?
... these questions affect other decisions

davidwood: big ups to my bro PatH for forcing the WG to adopt philosophical rigor in our terminology

,me , yo

<davidwood> Subtopic: Islands 🌴

<pfps> ?? to David's channelling of Andy

davidwood: in AndyS's island terminology, two graphs may use a uri in the 4th slot to mean different things

AndyS: the island idea was that there's a *social* step of assembling the data, and we're interested in that step

PatH: does it have technical consequences?

<davidwood> Pat said, "What [2] says is that *the same* URI when used in one graph can mean something completely different when used in another graph, and that *this is perfectly correct* and even in fact *consistent*. What this means is that every URI in every graph is interpreted locally to that graph, which in effect makes every URI into a blank node (since this is how blank nodes are interpreted.) This is dissolving the entire Web in a kind of universal solvent." (w

PatH: must the machinery support it?
... the obvious consequence is that the machinery that we have shouldn't force false consequences

<PatH> that was andy

<PatH> btw, that mention of bnodes was wrong, I acknowledge.

davidwood: in linked data, we say that using the same IRI in different places means the same thing.

AndyS: i think trying to address this technical hampers progress because we assume there's a single technical solution
... saying that "there's good practice and bad practice" is a weaker way forward

PatH: what "less ambitious" solution do you have in mind?
... there are datasets out there, people use them in various ways

AndyS: we have claimed we will solve some use cases
... maybe that's too ambitious
... we don't want to solve those use cases, we want to give folks machinery to solve those use cases
... we just have to not mess them up

davidwood: separating tech from social issues is helpful

<sandro> http://www.w3.org/2011/rdf-wg/wiki/Why_Graphs

sandro: in editing Why_Graphs this AM, these are all things that people want to standardize
... i don't think you can do any of these 5 things without defining semantics to trig
... how can i do <shared web crawler> and <archiving web crawler> in the same world?

<PatH> +1 sandro.

sandro: all use trig as a simple and obvious solution but they use it with different semantics
... could scribble into trig some info about how it's being used
... i think 2 and 3 share a semantics, and 4 just says you need bnodes shared between graphs
... 3 semantics:
... .. relation between name and graph is log:semantics
... .. relation between name and graph is owl:sameAs
... .. no relation between name and graph

<sandro> <a> owl:sameAs { <s> <p> <o> }

<zwu2> sounds a bit odd :)

ivan: so for owl:sameAs, an RDF graph becomes an OWL individual

MacTed: when i say "Joe" and i say <http://joe.example/#> i mean the same joe
... when you say "Joe" you mean Joe Jr.

<sandro> pfps, in OWL2 is an owl:Ontology a kind of individual?

MacTed: likewise when you say <http://joe.example/#> you mean Joe Jr.

<pfps> sandro, you just asked a question that does not really have an informal answer

<sandro> pfps, do you agree with AZ? (No in Direct Semantics, Yes in RDF-based semantics) ?

ericP: when i write a language, i expect the compiler to give me errors

PatH: you can expect to discover inconsistency
... the role of semantics is to deliver to you the fact that there's an abberation

MacTed: i have the impression that folks are trying to prevent such abberations from occuring

PatH: i don't think that [preventing abberations] can be done

<AZ> isn't TriG just a syntax?

<pfps> sandro, in OWL 2 Direct Semantics owl:Ontology does not appear

PatH: if an IRI is used as a graph label in a trig doc, and used as a label for another graph in another doc, is it the same thing?

AndyS: i've never seen it meant to label different things
... if it's contradictory, you've screwed up

sandro: i think the labeling relation is different
... (generally)

AndyS: if you allow that, you'd allow it to be a partial description

<AZ> +1 ericP

<Souri> I agree with MacTed: aberrations can happen within a single graph or when you merge multiple graphs ... a validation procedure can point it out ... that's all we can do

ericP: i think the common usage of SPARQL gives the answer here
... and that we should say that the triples associated with a label mean that labeled graph has at least those triples

zwu2: can we treat quads as syntactic sugar for reification
... ?

sandro: if we figure out how we want to use quads, we can derive how that looks in triples

PatH: +1 to sandro
... treating it as reification isn't consistent with this loose merging story, at least not without some work

<sandro> sound problems

<PatH> hiccups?

pchampin: we are talking about what we want to do with a trig file rather than what it means

<PatH> speak veeerrry slowly

<Arnaud> phone over ip or cell phone?

<sandro> pchampin, SORRY but we really can't understand you.

<pchampin> I think I'm gone sorry

pchampin, can you write your point?

<pchampin> pchampin: shouldn't we focus on what a trig file *means*, rather than what we will *do* with it?

davidwood: we've come back to this point several times: specifically, what do we want to do with a quad

<pchampin> pchampin: the question might be harder to answer, but then the answer to the other questions would follow

davidwood: is it fair to say that these five use cases are divergent enough to keep us from making a solution?

<sandro> http://www.w3.org/2011/rdf-wg/wiki/TF-Graphs-Designs

sandro: in the Why_Graphs, if you use trig in the intuitively obvious way, you end up with inconsistent uses
... but you can use it consistently in any of the 6 ways used on http://www.w3.org/2011/rdf-wg/wiki/TF-Graphs-Designs

AZ: trig is just a syntax

<AndyS> The SPARQL dump/restore is priority A in the original list (#1.5)

AZ: using trig solves the problem at a syntactic level
... we can could agree on the syntax first, and then derive the semantics

<AndyS> not dropped from my end :-(

<sandro> I think it's fine to use TriG as a default/example format for now.

ericP: is there a clear winner on http://www.w3.org/2011/rdf-wg/wiki/TF-Graphs-Designs ?

sandro: i pushed for #3
... AndyS and steve pushed back because of scale implementation costs
... i now like 6, but need to work out tech details

<sandro> NOT "scale". Steve's concern was a CONSTANT time cost.

<sandro> (or linear)

PatH: re: picking a syntax and deriving the semantics, these semantics are interchangable
... in trig, there are cases where the 4th column is a label for something like time
... thinking of these things as graphs doesn't fit with all of the intuitions we want to express

AZ: +1 to PatH

<AndyS> That wasn't my concern. 1) feels too much like complete replumbing to the deployed data web. (2) explaining it to people unless we define graph literals in Turtle.

AZ: with one syntax, we have a way of express stuff that we other way we can't express
... we could standardize trig and nquads

<sandro> sandro: TriG and N-Quads prejudice against solutions like Graph Objects (N3).

sandro: those prejudice against solutions like Graph Objects (N3)

<PatH> Trig prejudices against 4th field as a time parameter.

<sandro> Andy: as a group, I don't think we're sharing and building on each other's ideas

<zwu2> honestly, if we cannot reach a decision, then we are not ready

or it's too late

or it's hard

<PatH> i feel like I am making progress, for one.

<AndyS> Several solutions are great, if it were a clean sheet of paper.

<zwu2> bye

<PatH> bye

<davidwood> http://www.w3.org/2011/rdf-wg/wiki/Scribes

Summary of Action Items

[End of minutes]

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WARNING: Bad s/// command: s/@@1/http://www.w3.org/2011/rdf-wg/wiki/Why_Graphs
Succeeded: s/OWL/OWL2/
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Found ScribeNick: ericP
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WARNING: No "Present: ... " found!
Possibly Present: AZ AlexHall Andy AndyS Arnaud David_Todd FabGandon Guus Ivan LeeF MacTed OpenLink_Software P14 P2 P30 P32 P5 P8 PROPOSAL PatH Sandro Souri Subtopic antoine bhyland cygri davidwood ericP joined mhausenblas pat pchampin pfps rdf-wg scribenick swh trackbot yvesr zwu2
You can indicate people for the Present list like this:
        <dbooth> Present: dbooth jonathan mary
        <dbooth> Present+ amy


WARNING: No meeting chair found!
You should specify the meeting chair like this:
<dbooth> Chair: dbooth

Found Date: 29 Feb 2012
Guessing minutes URL: http://www.w3.org/2012/02/29-rdf-wg-minutes.html
People with action items: 

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