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[Minutes] 4 Nov 2002 TAG teleconf (query/schema consistency, fragments in XML, Arch Doc)

From: Ian B. Jacobs <ij@w3.org>
Date: Mon, 04 Nov 2002 18:12:25 -0500
Message-ID: <3DC6FED9.7080707@w3.org>
To: www-tag@w3.org

Dear www-tag,

Minutes from the 4 Nov 2002 TAG teleconf are available
as HTML [1] and as text below.

  - Ian

[1] http://www.w3.org/2002/11/04-tag-summary
Ian Jacobs (ij@w3.org)   http://www.w3.org/People/Jacobs
Tel:                     +1 718 260-9447


    W3C | TAG | Previous: 28 Oct teleconf | Next: 11 Nov

            Minutes of 4 Nov 2002 TAG teleconference

    Nearby: IRC log | Teleconference details ? issues
    list ? www-tag archive

1. Administrative

     1. Roll call: TBL, SW (Chair), TB, DC, NW, PC, RF,
        IJ (scribe). Regrets: DO, CL
     2. Accepted 28 Oct minutes
     3. Accepted this agenda
     4. Next meeting: 11 Nov. Regrets: RF (and possibly
        for 18 Nov).

   1.1 Meeting planning

     TAG presentation at AC meeting

      * Resolved: Approved TAG summary for AC (TAG-only).
      * Action SW, TB, DO: Send slides for AC discussion
        to TAG for review by 11 November. Review to take
        place primarily by email.

     TAG face-to-face meeting

    SW: I imagine four slots. One on namespace docs, one
    on AC meeting prep. Other two? See proposal from Tim
    Bray (TAG-only)..


           DC: Let's talk about document formats.
           SW: Please email me input to the ftf agenda by
           the end of this week.
           DC: Arch doc doesn't say much about a
           self-describing Web (following your nose from
           one doc to another to build context).
           DC: TBL, do you believe this is web arch doc?
           Can we discuss this at the ftf meeting? TBL
           can you write something in advance of the ftf
           SW: See RF's posting from today, which I think
           touches on this topic somewhat.
           DC: I hadn't read it from that angle.
           DC to TBL: Have you written on learning what
           document X means by following links from X->Y,
           where you know what Y is?
           TBL: I think that's captured by "grounded
           documents" in "Meaning".

    Action DC: Review Meaning to see if there's any part
    of self-describing Web for the arch doc.

    Completed Action TB 2002/10/28: invite Jonathan
    Borden to the meeting (afternoon) to discuss RDDL.

    TB: Bad news is that Jonathan won't attend meeting;
    Good news is that JB and I have reached agreement and
    I will be posting something about RDDL in the next
    few days.

2. Technical

      * 2.1 Potential issue re consistency XQuery/Xschema
      * 2.2 Use of fragments in SVG v. in XML
      * 2.3 Findings
      * 2.4 Architecture Document
      * 2.5 Postponed

   2.1 Potential issue re consistency XQuery/Xschema

    See issues from TB and responses from PC (TAG-only).


           TB summarizes his issues: I have some
           technical issues with directions proposed by
           Query WG. Sharpest aspect is that parts of
           Query require XML Schema semantics. I sent
           info to XML Query WG; received a short reply;
           since then I've received longer replies from
           individuals of the group.
           My latest message is an attempt to break down
           the problem. This may be a process issue
           rather than an arch issue. We are moving
           beyond DTDs (after decades) into new
           territories of schemas. It seems to me at this
           point highly architecturally unsound for any
           really important Recommendation to bet the
           farm on a particular schema language. XQuery
           is bigger than it needs to be. The WG has done
           the sensible thing of defining Basic Query
           (leaving out most of schema bits). There needs
           to be architectural pressure on groups to do
           less; ship sooner; ship simpler.
           PC: Sorry for not replying in a more timely
           fashion to TB's points. On the topic of
           required integration: WG chartered (twice) to
           use XML Schema. There haven't been comments
           prior saying that this is a bad thing. If this
           dependency is to be changed, then Query WG
           needs to be rechartered.

           Firstly, I am surprised that TimBray is not
           encouraging interdependence between w3c specs
           - see HTML and Xlink discussion - PC

           PC: This makes this a process issue. IMO, the
           primary concern in public fora is not
           dependency on xschema. But rather whether
           update language is critical (public split
           50/50). On living in a multiple-schema world:
           Just because someone waves a standards banner
           does not mean that the XML Query WG has to
           change its plans and delay its work to pay
           attention to such a banner waver.: Perhaps the
           XML world needs an abstraction that would
           include the various schema languages. I think
           there's a work item in the schema charter that
           covers this item.
           From XML Schema WG charter: "interoperability
           with other schema languages such as RELAX-NG
           and Schematron"
           On item three on simplicity: We have worked
           hard to meet our requirements. To come along
           and say that the requirements are too big
           surprises me. I don't think that WGs at W3C
           should be constrained to pursuing only small
           specs.. Basic Query handles Schema Part 2. If
           we publish Basic Query as our only
           deliverable, we would not meet our
           requirements. I don't think that at this point
           in time we should split our deliverables given
           the progress we've made on the document. I
           think it's ok that the query spec is big. Some
           of the size has to do with clearer
           expectations about interoperability. TB has
           identified a long-term goal -- clearer
           relationships among schema specs -- but I
           don't think that this should affect Query 1.0.
           There are a number of XQuery 1.0
           implementations, even prior to last call (both
           Member and non-Member implementers). So TB's
           arguments sway me less since we have so much
           implementation experience that suggests we are
           doing the right thing.
           DC: Is PC arguing that this or is not a TAG
           PC: Could be that the TAG issue is on multiple
           schema languages. Perhaps we could synthesize
           an abstract model for PSVI processors.
           DC: Is there an issue in the first place?: I'm
           convinced there's an issue given the
           substantive email exchanged.
           TB: Tie-in to XLink is a big bogus; the
           arguments in that case were purely technical,
           not about it being a W3C spec.: In the
           community of Web designers, there is a wave of
           horror at the astounding complexity of schema
           and xpath 2.0. A strong feeling that something
           has gone amiss somewhere.
           DC: I have heard similar.
           TB: I am not simply running off at the mouth
           here, but I think accurately representing a
           feeling that's out there.

           DanCon, you wanted to share concerns from the
           public about XML schema "leaking" into other
           specs; mostly XPath and to say that nearing
           last call is *exactly* the time to revisit and
           confirm or reconsider requirements.

           Timmit, you wanted to say that this is
           primarily an architectural issue in the sense
           of high-level modular design. It is a question
           of whether a flexible interface to the schema
           language should be provided. Of course the
           process and social issues are intertwined.

           TBL: The question is architectural (whatever
           the charter said).: Modularity is a good
           thing; can the specs be more modular? PC and
           TB do talk to different people (and it's good
           to hear from all of those people). It would be
           obviously costly to do anything to XQuery. I
           read Xquery and it seemed pretty
           straightforward to me. PC's social point holds
           (cost of change).
           TB: Query allows querying by types. Allowing
           query by those 19 data types seems reasonable.
           [TBL summarizes that TB's concern is about the
           dependency on part 1 of XML Schema.]
           SW: Is the focus on a dependency on a single
           schema language or more specifically on XML


           [Scribe is unsure whether this substitution is

           TB: I think that PC is correct -- there's a
           key technical question about whether XML
           Schema is a cornerstone of future XML specs.

           well, tim, techincally, XML Schema part 2
           depends on XML Schema part 1.

           PC: I think the issue is more about multiple
           schema languages.

           Timmit, you wanted to say that this sort of
           choice has to be made in each case on its

           TBL: I am concerned by extreme stances such as
           "one should one always use w3c specs"; each
           case is different. Several good principles
           here - reuse stuff; modularity. Need to
           consider each case. Just talking about the
           schema, case I think that it's not interesting
           to reset the Query WG. What is possible is for
           someone to find a clever way of achieving what
           is required. I haven't understood whether
           "Basic" is what TB needs. Is Basic what TB
           prefers, or is Basic not adequate (and needs
           SW: Please frame comments in terms so we can
           define this issue.
           TB: I think that it's a good thing to have
           lots of schema languages out there since this
           area is new. We don't have enough experience
           to know which schema language meets which
           needs. I highly approve of XQuery Basic and
           would strongly recommend that the WG release
           that on a separate Rec track. It might even
           shorten time to Recommendation (for that part
           of the spec). I have argued (with specifics)
           about how query/schema can be decoupled. I
           haven't heard substantive replies to my
           specific syntax.

           TB: issue proposal: "Schema languages: What
           can be said about multiple existing schema
           languages and their appropriate uses in W3C
           and the Web more generally?"

           TBL: More specific than "What can be said
           TB revised proposal: "Given the existence of
           more than one XML schema languages; what
           architectural implications does the use of a
           particular language have? To what extent is it
           useful to bind to all schema languages or a
           particular one?"
           DC issue proposal: "To what extent should
           schema be integrated into xpath and xquery?"
           At confs I hear concerns about XPath.
           NW: I have a lot of the same concerns as TB.
           Though I'm not sure what the issue is,
           exactly. I think the pragmatic issue will be
           setting the conformance levels right.
           Substitution groups and inheritence look like
           they'd be hairy to decouple.

           sigh. conformance levels are evil. This was a
           priniciple of XML 1.0 (which XML 1.0 didn't
           quite meet, actually) and it continues to be

           PC: What about extending DC's proposal to
           xforms and wsdl?
           DC: Not concerned about those as much as
           xpath, and xquery.
           NW: I'd support DC's proposal
           PC: I vote against the issue as proposed.
           XQuery 1.0 handles DTD and XML Schema. It's
           not been on the WG's work plan to handle other
           schema languages. And it seems that the XQuery
           WG charter has as a work item addressing
           additional schema languages. I don't
           understand why the TAG has to take this up
           since the WGs have items on their work plans.
           NW: I don't think that there's evidence that
           xquery and xpath will support xml schema and
           dtds equally well.
           RF: There seems to be an awful lot of support
           for Relax
           SW Proposed: Adopt as a new issue "To what
           extent should xml schema be integrated into
           xpath and xquery?"
           PC: I oppose this as an issue; I don't see
           what the architectural issue is from this
           For: DC, TB, NW.
           Abstain: TBL, RF, SW
           PC: If there an arch issue, I think it's about
           how schema languages interrelate. I'd like to
           take offline with TB and refine this.

    No issue accepted at this time. No action item

   2.2 Use of fragments in SVG v. in XML

      * Action DC 2002/09/26: Describe this issue in more
        detail for the TAG. Done

           DC proposed issue: "Use of fragment
           identifiers in XML". I think that CL might
           disagree with me, but I take that as evidence
           that there is an issue.
           TB: Is there not already an architectural slam
           dunk: RFC2396 says that what comes after # is
           up to the spec.
           DC: There are cases where two specs define
           what happens. It seems to me that it means
           something, but it doesn't have to be
           exhaustive or exclusive.
           TB: I could almost see a principle that says
           "When there is a language that might be served
           wtih one of multiple media types,
           inconsistencies in meaning for frag ids is
           SW: RFC2396 also discourages inconsistency.
           TBL: We can ack the inconsistency in the
           architecture (e.g., when coneg is used). You
           can serve an HTML page as text/plan. You could
           serve up, similarly, a bag of bits using the
           appropriate mime type to give the meaning of a
           dog or car.
           TBL: I have resisted bringing in mime types.
           I've become more comfortable with the idea of
           using mime types to give a particular view on
           data.: I think there is an issue here that we
           should write up. Fortunately, I think we can
           write it up and resolve it.
           [Straw poll]
           PC: I'm uncomfortable about doing this without
           Chris Lilley present.
           DC: That doesn't convince me that we shouldn't
           call the question, see if there's support
           today, and moving on.
           SW: Active support for the proposed issue?
           For: NW, TBL, DC, SW, RF
           Abstain: PC, TB

           People would like to be able to inject
           processing instructions (not PIs, but
           semantics) into fragment identifiers. That's
           where I'm feeling the pain today.

           Resolved: Accept new issue fragmentInXML-28.
           Action IJ: Add fragmentInXML-28 to issues

   2.3 Findings

    See also: findings.
     1. Findings in progress:
          1. deepLinking-25
               1. TB 2002/09/09: Revise "Deep Linking" in
                  light of 9 Sep minutes. Status of
     2. Findings versioning
          1. SW 2002/09/09: Discuss with IJ versioning of
             findings. Done.

    On findings versioning:

           DC: Formalizing this is burdensome; I feel
           differently for Tech Reports.
           SW: I didn't want people to refer to things
           that would change.
           DC: Such is life. Do other people really want
           to do this?
           SW: For me, this is what I'd like for
           PC: Works for me.
           NW: It works for me, too.
           IJ: Number of findings per year (6 in 2002)
           seems manageable.

    Resolved: Accept this proposal for the time being.
    Action IJ: Send this policy to www-tag and make
           available from/on findings page.

   2.4 Architecture document

    See 29 Oct 2002 Architecture document
     1. Completed action RF 2002/09/25: Propose a rewrite
        of a principle (rationale -> principle ->
        constraint) to see whether the TAG prefers this
        approach. It was suggested that the example be
        about HTTP/REST, as part of section 4.
     2. Completed action TBL 2002/09/25: Propose text on
        information hiding. (From 24-25 Sep TAG ftf: "The
        principle of information-hiding is contrary to
        global identifiers....Shall we put in the
        document something about information
        hiding/independent design of orthogonal specs?
        You should should not be able to write an xpath
        to peek into http headers....") [Done]
     3. Action CL 2002/09/25: Redraft section 3,
        incorporating CL's existing text and TB's
        structural proposal (see minutes of 25 Sep ftf
        meeting on formats).
     4. Action NW 2002/09/25: Write some text for a
        section on namespaces (docs at namespace URIs,
        use of RDDL-like thing).
     5. Completed action DC 2002/10/31: Resend redraft of
        arch doc section 2.2.1 on URIEquivalence-15. DC
        and IJ discussed on 30 October. Should IJ
        incorporate those comments in next draft?
     6. Action IJ: Incorporate DC and IJ comments about
        URIEquivalence-15 into next arch doc draft.
     7. Completed Action IJ 2002/10/28: Include link to
        IRI issue from this point; leave as good practice
        note. Done in 29 Oct 2002 Architecture document.


           Roy writes "I give up" as if to say "please
           withdraw this action" but I found his message
           quite responsive to the action.

           RF: Regarding earlier question: are xquery and
           xml schema orthogonal?
           TB, DC: I found the approach appealing.
           IJ, SW: Same here.
           IJ: "Change is inevitable, and therefore
           evolution should be planned." Seems like
           "evolution shoudl be planned" is for agents,
           not the system. Does "requirements" mean
           requirement on the designers or the system?
           RF: "The system needs to be be able to evolve
           since change is inevitable."
           TB: "Evolution should be planned *for*; when
           change happens things should not fall apart."
           TBL action regarding info hiding done.
           CL Action about chapter three not done.
           IJ: What are our expectations for doc before
           AC meeting?
           PC: I am more comfortable approving 29 Oct
           draft and approving a bigger change at the ftf
           DC: I'd like IJ to get as much done as
           possible by 13 Nov, with approval with one
           other TAG participant's review.
           Resolved: We might not get a doc out by 13
           Nov, but ok for IJ + two other participants
           (for this draft) sufficient to get to TR page.
           IJ: I will try to get a draft with some of
           RF's proposals by Thursday.

           TB, SW: We commit to read and give feedback.

           if it's out by Thu, I intend to read it by

   2.5 Postponed

     1. IRIEverywhere-27
          1. See comments from Paul Grosso (asking the
             TAG to do this quickly).
             SW: This will be a priority agenda item for
             the 11 November meeting.
             Action IJ: Invite Martin Duerst to the 11
             Nov meeting.
     2. Status of URIEquivalence-15. Relation to
        Character Model of the Web (chapter 4)? See text
        from TimBL on URI canonicalization and email from
        Martin in particular. See more comments from
          1. CL 2002/08/30: Ask Martin Duerst for
             suggestions for good practice regarding URI
             canonicalization issues, such as %7E v. &7e
             and suggested use of lower case. At 16 Sep
             meeting, CL reports pending; action to send
             URI to message to TAG.
     3. xlinkScope-23
          1. Coordination with XML CG? See Notes from XML
             CG call 10 Oct 2002 (Member-only)
     4. namespaceDocument-8
          1. Action TB 2002/09/24: Revise the RDDL
             document to use RDF rather than XLink. Goal
             of publication as W3C Note.
     5. contentPresentation-26
          1. Action CL 2002/09/24: Draft text on the
             principle of separation of content and
             presentation for the Arch Doc.
     6. rdfmsQnameUriMapping-6
          1. The Schema WG is making progress; they will
             get back to us when they're done. See XML
             Schema thread on this topic.
     7. uriMediaType-9:
           + Action DC 2002/08/30: Write a draft Internet
             Draft based on this finding (Deadline 11n
             Nov). This action probably subsumes the
             action on TBL to get a reply from the IETF
             on the TAG finding.
     8. Status of discussions with WSA WG about
        SOAP/WSDL/GET/Query strings?
           + DO 2002/06/24: Contact WSDL WG about this
             issue (bindings, query strings and schemas)
             to ensure that it's on their radar. See
             discussions from 9 Sep TAG teleconf.

     Ian Jacobs, for TimBL
     Last modified: $Date: 2002/11/04 22:53:25 $
Received on Monday, 4 November 2002 18:12:27 UTC

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