- From: Ian B. Jacobs <ij@w3.org>
- Date: Tue, 30 Jul 2002 08:38:03 -0400
- To: www-tag@w3.org
Hello,
Minutes of the 29 July TAG teleconf are available
at HTML [1] and as text (below).
Next TAG teleconference: 12 August.
_ Ian
[1] http://www.w3.org/2002/07/29-tag-summary
--
Ian Jacobs (ij@w3.org) http://www.w3.org/People/Jacobs
Tel: +1 718 260-9447
==========================================================
W3C | TAG | Previous:22 Jul | Next: 12 Aug | IRC log
Minutes of 29 July 2002 TAG teleconference
Nearby: Teleconference details · issues list ·
www-tag archive
1. Administrative
1. Roll call: DO, TB, TBL, DC, RF, CL, IJ. Regrets:
NW, SW, PC
2. Accepted 22 July minutes
3. Accepted this agenda
4. Next meeting? 12 Aug. Regrets: DO, CL
5. September meeting arrangements
Action TB: Send info about hotels to TAG. Done.
1.2 Completed actions
1. RF 2002/06/24: Write a paragraph on technical and
political aspects of URIs and URI References.
(done)
2. DC 2002/07/08: Propose text for section 1.1 (URI
Schemes). Done, see URI FAQ.
3. Update and publish these findings as accepted.
Action IJ and NW (done).
1. Using QNames as Identifiers
2. Consistency of Formatting Property Names,
Values, and Semantics
4. CL: Send copy of information sent to tag
regarding RFC3023Charset-21 to www-tag. (Done)
2. Technical
1. Findings, architecture document
2. httpRange-14
3. URIEquivalence-15
4. Postponed
2.1 Findings in progress, architecture document
See also: findings.
1. Architecture document
1. Action CL 2002/07/08: Propose text for
section 2 (Formats). (Sent to TAG; CL to
publish).
2. Action DC 2002/07/08: Ask IESG when they
decided not to use HTTP URIs to name
protocols.
3. Action TBL (formerly assigned to DC): Create
a table of useful URI properties.
4. Action IJ 2002/07/08: Produce WD of Arch
Doc. Harvest from DanC's URI FAQ. Deadline
30 August.
2. Internet Media Type registration, consistency of
use.
+ Action PC 2002/07/08: Propose alternative
cautionary wording for finding regarding
IANA registration. Refer to "How to Register
a Media Type with IANA (for the IETF tree) "
2.2 httpRange-14
1. httpRange-14: Need to make progress here to
advance in Arch Document. See thread started by
Tim Bray.
1. Completed action SW 2002/07/22: Persuade
TimBL to write an exposition of his position
on httpRange-14. (Done; see TBL document).
See also history of fragment ids from Roy.
[Ian]
TBL: In my doc, I explain why the alternatives
don't work.
DO: I'd like a week to read up on this.
TB: If TBL convinces us that HTTP URIs are for
docs only, where would we write this? What are
the practical consequences? Where would this
show up in the arch document if we agreed with
TBL?
TBL: s/resource/document, for example. So
representations don't apply to mailboxes,
e.g..
TB: It would certainly add focus to the debate
if we had some actual practical consequences.
[ChrisL]
TBL's HTTP-URI document seems to equate
'document' and 'any collection of bits'
TBL: Practical consequences:
1. RDF Core would have to stop using
doc-looking URIs to refer to some classes.
RF: I am certain Dublin Core doesn't need to
change.
TBL: The URI of title has no hash, so is
confusable between document/resource.
RF: It doesn't matter.
TBL: Before RDF, people haven't used URIs to
refer to other things than web pages.
[ChrisL]
Never understood the RDF way of using # to
mean "not za fragment identifier"
[Ian]
DC: There are namespace names.
[ChrisL]
People do indeed use URI to refer to things
other than web pages.
[Ian]
TBL: If it doesn't affect the software, it's
irrelevant philosophy.
[ChrisL]
No, the *definition* of dc.title has that
length
[Ian]
DC: I would note that the XML Schema WG used
URI refs to talk about data types. They use
hash marks in them.
RF: What about POST?
[DanC]
"aren't fragment identifiers"???
[Ian]
CL: This use of "#" as non fragment id's has
always struck me as odd. Why is a fragment
special?
TBL: With and without a hash is fundamentally
different. A URI Ref is a completely different
animal than a URI. Need to look at another
spec.
CL: But the history is that these were the
same thing.
TBL: No, defined in same spec, but not the
same thing. When you use "#" in an HTML doc,
not a huge effect. But in RDF, a huge
difference - takes you into abstract space.
CL: I don't like the implication that non-RDF
languages are non-semantic. What is good
practice for using the "#"?
TBL: You define that in the format spec, part
of MIME registration.
CL: Most specs other than RDF use sense of
"fragment" (whether temporal or
element-based).
[DanC]
really? there are ways to refer to 7 seconds
into a video? I've been waiting for those, but
haven't seen them.
[DanC]
[yet somehow, magically, calling it a
"Document" precludes cars. Pls pick one side
of your mouth to speak out of, timbl]
[Ian]
TBL: Ambiguity about owner's intent of what is
identified.
[ChrisL]
WebCGM fragment syntax
http://www.w3.org/TR/REC-WebCGM/REC-03-CGM-IC.
html
[Ian]
DC: What if it's ambiguous but two things
identified are identical?
[ChrisL]
SVG fragment identifiers
http://www.w3.org/TR/SVG/linking.html#SVGFragm
entIdentifiers
[Ian]
DC: Can you point to a car that's also a web
page?
TBL: For me that's incoherent.
DC: But in common sense, you can't post to
documents.
TBL: Documents do not have a physical
presence; cars do. No way I can determine
whether I can use the URI to talk about a Web
page since owner may have not meant it that
way.
[ChrisL]
http://www.w3.org/TR/smil20/smil-timing.html#T
iming-HyperlinkingTiming
[Ian]
RF: You can do this with RDF.
[TBray]
what Roy said
[ChrisL]
Hyperlinking and timing
A hyperlink into or within a timed document
may cause a seek of the current presentation
time or may activate an element (if it is not
in violation of any timing model rules).
[Ian]
TBL: But this won't retrofit to 10 billion
existing web pages.
RF proposal: Given lack of any other
assertions, you can assume that a URI refers
to a document. You are saying that because you
don't have a default, therefore the entire
HTTP namespace should be your lowest common
denominator.
TB: A URI is a string you can compare. An HTTP
URI can be dereferenced. The Web arch doesn't
allow you to know what the resource is. This
is why RDF is a good thing. Allows you to make
such assertions. Once you have RDF, I still
don't see why you need to limit the range of
HTTP URIs or other URI schemes.
[DanC]
my car is on the web.
[Ian]
CL: The car is a physical object, but it's not
on the web. the concept is a title but is not
on the web. You can point to the concept of
"title". If you can point to "title", you can
point to "car". I don't think you can point to
a "title". You can point to a document where
people say what they mean by title. Even with
"#" you are pointing to a piece of a document.
That piece may be an assertion. But could be
pulled out and put in its own document, and I
could refer to it without a "#".
DC: You can always use the URI for a Web page.
If the Webmaster has also said that that URI
identifies a car, that's fine.
TBL: When I do an HTTP transaction, can I
store the results in RDF?
DC: Yes. In the example of my Web page, the
Web page is a car.
TBL: What if a Web page talks about another
Web page that talks about a car?
http://myexample.org/mypage23 ->
http://www.w3.org/mystuff -> car
TBL: As author of the first URI I assert that
it identifies the second page. I assert that
they identify the same thing. Not sure that
identical if you get different pages back from
the Web.
RF: The statement HTTP URIs identify documents
is false.
TBL: We are working out a consistent set of
terms. If "document" is the wrong term, that's
fine; we can work out another. I"m interesting
in what machines can do.
[ChrisL]
I propose that Tim's definition of "document"
is any bag of bits
[Ian]
RF: The software disagrees with you. I can't
define proxies in your terms.
TBL: You can: where you say "resource", say
"document". It's sufficiently generic to cover
your proxies.
[DanC]
If timbl really means that roy could
s/resource/document/g, it's much cheaper for
timbl to s/document/resource/g.
[DaveO]
heh
[Ian]
TBL: People think of the term "document" in a
particular way, but that was the term as I
originally intended (in an abstract sense).
RF: What do "wais:" URIs identify? Search
services. It's an information retrieval
protocol.
[ChrisL]
so they identify a search engine
[DanC]
btw... timbl mentioned the cyc ontology; it
really does have a wealth of nifty and
relevant stuff on this topic...
http://www.cyc.com/cycdoc/vocab/info-vocab.htm
l
[Ian]
RF: When you access a wais resource through a
proxy, you are saying - give me a
representation of this resource through wais.
[DanC]
timbl:Document = cyc:ConceptualWork, I think.
[ChrisL]
(this is the general gatewaying problem, which
was established at Cern)
[Ian]
DO: This is a point that has been skirted
around -use of proxies. Could RF write up
something on proxies?
RF: I will read TBL's doc first.
TB: Suppose I believe that DC's car URI really
denotes DC's car. Suppose I write a bunch of
stuff in RDF about the car, and I have a
carfinder service online to sift among cars
out there. All that is logical and
self-coherent and causes no heartburn. Suppose
RF doesn't believe it's a car but the URI
identifies a Web page. He writes a bunch of
other RDF that talks about the Web page. Our
assertions are not interoperable but could be
bridged with some metadata. But at the end of
the day, so what? The idea that you will have
universal agreement on what is identified is a
chimera. But what's the difference?
[ChrisL]
(sounds like "do we assume all assertions are
true")
[Ian]
TB: If we need to work together, we will do
the work to understand each other.
TBL: Cataclysmic interoperability problem is
the heartburn.
TB: That's the reality of life. You can't make
it go away.
[TimBL]
You CAN
[Roy]
given any identifier, I can make a webpage out
of it
[Ian]
TB: Another spin: suppose I want to make
assertions that the Web page is a standin for
W3C. Are Josh's views and mine that
inconsistent? Perhaps on the surface, and we
would need to work together. But I don't
believe this problem can go away.
TBL: You can make it go away. You can merge
data when using same ontologies. The situation
TB describes is frightfully messy to me. Where
you have to do a massive conversion when
merging data.
[TimBL]
x [ is fff of x ]
x -> [ is fff of x ] mapiing woul dhave to be
introdde between 2 incompatible webs
Si
<xml:lang="fr">si</>
[DaveO]
or <xml:lang="sp">si</> ?
[ChrisL]
<foo xml:lang="es">Si</foo> <!-- I suggest -->
[TimBL]
(On the contrary it does mean that TimBL's
stuff breaks when Roy's data is introduced)
[Roy]
then it is already too broken to use
[Ian]
DC: TimBL wants a guarantee that someone will
never find a car at the other end.
[DanC]
it's not "I can't know that". TimBL's saying
"I consider that false."
[Ian]
RF: You need RDF to know what my URI
identifies. If you want to be able to reason
using this URI in an unambiguous manner, then
you will need more information.
IJ: Then what does it mean that a URI means
the same thing in any context?
[ChrisL]
isn't this an arcrole to say how much
dereferencing is happening?
[Ian]
TBL: In general, there is an axiom that a URI
identifies one thing in all cases.
[DanC]
I don't believe that axiom any more, btw,
timbl.
[Ian]
TBL: If you use a URI in a relationship, it
can indirectly refer to other things.
[ChrisL]
except in the trivial case - it identifies the
resource that you get by dereferencing it
[DanC]
Chris, that's one (coherent) position: there
are different ways to point. *p vs **p, in a
sense.
[TimBL]
Roy has said that he can't use TimBL's scheme
because proxies won't work because he thinks
tim's system has no difference between
document an representation, but there he i
swrong, presumbably because he hasn't read
TimBL's stuff yet.
[ChrisL]
arcrole of "the organisation that published
this page"
[Ian]
TB: I suggest we publish these logs and stand
back and see what happens on www-tag.
[ChrisL]
as opposed to, say, arcrole of "the isp that
hosts this page" or any other such arc role
[DanC]
In AaronSw's reply to TimBL
(http://lists.w3.org/Archives/Public/www-tag/2
002Jul/0319) I find much that I agree with.
[Roy]
Roy says that TimBL's document == resource and
therefore it is confusing to call them
documents
2.3 URIEquivalence-15
1. 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
Martin.
1. What should a finding look like for this?
[Ian]
TB: Martin has made a kind of overwhelming
case that we are stuck with char-by-char
equivalence. We should say "When composing
URIs, don't use percent-encoding unless you
have to, and use lower case when you do."
DC: If you mean the same thing, spell it the
same way. Someone may use e and E differently,
so you'd better have good information before
considering them to be equivalent.
TB: the cost seems to be too high for
considering %7e and 7%E to be different (see
MD's arguments).
DC: The cost of having receivers convert
things is astronomical. It's easy for us, on
the other hand, to say "use lower case when
you percent-escape."
[ChrisL]
(2) is always needed in HTTP, no?
[Ian]
DC: If you write href="~...", the client
better put a "~" byte on the wire, and not a
%7e
[ChrisL]
once it goes over the wire?
[Ian]
TB: Regardless of this, I think we can easily
achieve consensus that it's worthwhile to make
this point in the arch document. And make the
point that for max interoperability, don't
%-escape unless you have to, and use lowercase
when you do.
DC: If someone gives you a URI, don't screw
with it.
TB: Maybe not true: If a user types in a URI
that has a space, then you are required to %20
that.
DC: But in that case, the user didn't give a
URI.
TB: Right - if given a URI, don't scree with
it. if composing a URI, there are cases where
must escape things, others where shouldn't,
and if given a percent-escape, don't screw
with.
CL: You percent-escape Kanji as late as
possible.
DC: Spaces and Kanji characters -are they in
scope here?
CL: I'm happy to co-write a finding with
Martin.
RF: The href attribute is CDATA (or whatever).
[ChrisL]
anyURI
[Ian]
RF: The attribute value has to be translated
from xml entities to something that looks like
a URI. If there's a space into it, it needs to
be translated into a URI first.
DC: Test case: two documents fed to an xslt
processor. One has space, the other %20. The
namespaces spec says that these are URi
references. One guy spells the namespace name
with 7-bits, the other with more.
RF: Mozilla treats space as illegal char. IE
treats as auto-conversion to %20 (for href's
in general). IE sends out the space over the
wire.
[TimBL]
I have a feeling that there will probably some
situation where the TAG has to say: stop, do
it differently.
[Ian]
TBL: What's the next step? Continue from here?
Or have someone go off and work on it?
[DanC]
my test case is from a question of
interpretation sent to the XML Core wg (via
xml-names-editor or xml-editor or some such).
[TimBL]
Maybe we need a set of test cases.
[DanC]
(I'm not sure about my "if you mean the same
thing, say it the same way" position, now that
we get into the IRI territory)
[Ian]
CL: I'd like to see whether the "character
model of the web" says this.
TBL: Please keep this on agenda for next time.
2.4 Postponed
1. Status of discussions with WSA WG about
SOAP/WSDL/GET/Query strings?
+ ACTION 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 24 Jun TAG teleconf.
2. xlinkScope-23
1. Priority of this?
3. augmentedInfoset-22:
+ Request from Tim Bray to decide this issue
(disposition = closed). Pushback from Simon
St. Laurent.
+ ACTION DC 2002/06/17: Talk to XML Schema WG
about PSVI. Report to tag, who expects to
decide whether to add as an issue next week.
DanC has sent email; awaiting reply from XML
Scheme WG.
4. deepLinking-25
1. Action PC 2002/07/22: Ask Henrik Frystyk
Nielsen to provide us with a precis of the
ruling. Done: awaiting reply from Henrik.
5. uriMediaType-9: Status of negotiation with IETF?
See message from DanC.
+ Action TBL: Get a reply from the IETF on the
TAG finding.
________________________________________________
Ian Jacobs, for TimBL
Last modified: $Date: 2002/07/30 12:33:47 $
Received on Tuesday, 30 July 2002 09:10:27 UTC