subject:"What would break, a question for implementors\? \(was Re\: Is 303 really necessary\?\)"

On 11/9/10 6:57 AM, Ian Davis wrote:

On Tue, Nov 9, 2010 at 11:23 AM, Nathannat...@webr3.org wrote:

Pete Johnston wrote:

This document mentions the following class

It's all very simple really, when you remove all the conflated terms.

I am not conflating terms and nor is my example, but I think you are (see below)

What is this:

?xml version=1.0?
rdf:RDF xmlns:rdf=http://www.w3.org/1999/02/22-rdf-syntax-ns#;
xmlns:foaf=http://xmlns.com/foaf/0.1/;
xmlns:rdfs=http://www.w3.org/2000/01/rdf-schema#;
xmlns:wdrs=http://www.w3.org/2007/05/powder-s#;
xmlns:dbp=http://dbpedia.org/resource/;

dbp:Toucan rdf:about=http://iandavis.com/2010/303/toucan;
rdfs:labelA Toucan/rdfs:label
foaf:depiction
rdf:resource=http://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Pteroglossus-torquatus-001.jpg/250px-Pteroglossus-torquatus-001.jpg;
/
rdfs:commentThis resource is an individual toucan that happens to live
in southern mexico./rdfs:comment
wdrs:describedby
rdf:resource=http://iandavis.com/2010/303/toucan.rdf/
/dbp:Toucan

foaf:Document rdf:about=http://iandavis.com/2010/303/toucan.rdf;
rdfs:labelA Description of a Toucan/rdfs:label
rdfs:commentThis document is a description of the toucan
resource./rdfs:comment
/foaf:Document

/rdf:RDF

http://iandavis.com/2010/303/toucan is simply another name for whatever
the above is.

Nope. It's not at all. That text you include is the entity sent when
you issue a GET to the URI. Entity bodies aren't usually named on the
web. It's also a representation of
http://iandavis.com/2010/303/toucan.rdf

You are conflating the resource with the content of an HTTP message
sent to your computer.

You could interpret the tabulator property as meaning the entity
returned when you perform a GET on the URI contains the following
class

Hints:
- it's not a resource

It has a URI http://iandavis.com/2010/303/toucan.rdf, anything
identified by a URI is a resource.

Yes, in Resource Conflation lingo.

No, in reality.

A URI is an Identifier. Remember it stands for: Uniform Resource
Identifier. It should actually be: Universal Object Identifier or
Universal Entity Identifier or Uniform Object Identifier or Uniform
Entity Identifier.

URIs Identify Entities or Things. They can identify anything we can
imagine.

A Resource is a kind of Thing that has physical manifestation in a
specific realm. Yes, we are Resources, Documents, Widgets, but not
in the Web Realm.

You are conflating because Web != Real World. Thus, saying everything is
a Resource, when the rest of the world knows that everything is an
Entity or Thing or Object is conflation that leads to utter
incomprehension.

How do you think Object based systems work? How do you think Object
Oriented Database work? How do you think Object Relational Databases
work? How do you think Relational Databases work? How do computers
work? Is an Address the only way we use a Pointer? Do you seriously
think that the ubiquity of an HTTP network, where physical resources
represent Documents (e.g. HTML, RDF, XML etc..), warrants such overreach
and disregard for the past re. computer technology continuum?

Resource conflation days are numbered. Its usage and acceptence is
inherently inversely related to Linked Data concept comprehension.

Remember my statement above. Same applies to RDF = Linked Data, conflation.

- it's not a document

I think it is

It cannot be!

It resolves to a Document.

Without Documents how can one perceive anything across any medium?

- it's not an rdf document

I think it is

It resolves to a Document Type where the Content is expressed in on of
the RDF markup syntaxes.

- it's not a toucan

Agree. That text is not a toucan.

Yes, but for a different reason. The Toucan is the Referent of the URI.
This is how its always been, if it wasn't you wouldn't be reading this
mail via a computer system that uses pointers to create references that
enables us walk data structures, programmatically.

Kingsley

Best,

Nathan

Ian

Regards,

Kingsley Idehen
President CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)

2010-11-09 Thread Nathan

Kingsley Idehen wrote:

On 11/9/10 6:57 AM, Ian Davis wrote:

On Tue, Nov 9, 2010 at 11:23 AM, Nathannat...@webr3.org wrote:

Pete Johnston wrote:

This document mentions the following class

It's all very simple really, when you remove all the conflated terms.

it's a description.

I am not conflating terms and nor is my example, but I think you are
(see below)

What is this:

/
rdfs:commentThis resource is an individual toucan that happens
to live

in southern mexico./rdfs:comment
wdrs:describedby
rdf:resource=http://iandavis.com/2010/303/toucan.rdf/
/dbp:Toucan

/rdf:RDF

http://iandavis.com/2010/303/toucan is simply another name for
whatever

the above is.

You are conflating the resource with the content of an HTTP message
sent to your computer.

You could interpret the tabulator property as meaning the entity
returned when you perform a GET on the URI contains the following
class

Hints:
- it's not a resource

It has a URI http://iandavis.com/2010/303/toucan.rdf, anything
identified by a URI is a resource.

Yes, in Resource Conflation lingo.

No, in reality.

URIs Identify Entities or Things. They can identify anything we can
imagine.

A Resource is a kind of Thing that has physical manifestation in a
specific realm. Yes, we are Resources, Documents, Widgets, but not
in the Web Realm.

Resource conflation days are numbered. Its usage and acceptence is
inherently inversely related to Linked Data concept comprehension.

Remember my statement above. Same applies to RDF = Linked Data, conflation.

- it's not a document

I think it is

It cannot be!

It resolves to a Document.

Without Documents how can one perceive anything across any medium?

- it's not an rdf document

I think it is

It resolves to a Document Type where the Content is expressed in on of
the RDF markup syntaxes.

- it's not a toucan

Agree. That text is not a toucan.

Kingsley

Best,

Nathan

Ian

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)


On 11/9/10 11:22 AM, Nathan wrote:

Kingsley Idehen wrote:

On 11/9/10 11:10 AM, Kingsley Idehen wrote:


A URI is just an Identifier. We can Describe what isn't 
unambiguously Identified (Named); hence the use of Names since the 
beginning of shared cognition era re. human evolution.


A URI is just an Identifier. We can't  Describe what isn't 
unambiguously Identified (Named); hence the use of Names since the 
beginning of shared cognition era re. human evolution.




ex:about#toucan doesn't name a toucan though, it names, or refers to, 
toucan, as described by ex:about




Yes, it refers to Toucan by .. ?

Put differently, Toucan (a Thing observed by the Describer) is the 
Referent of the Identifier (URI). Thus, the URI is used to distinguish 
the Subject (Tucan) from the surface (Document) from which we perceive 
its Description.


Referent, Identifier, Resource trinity :-) The 3 elements  (in 
combination) deliver comprehensible Representation, to a given beholder.


--

Regards,

Kingsley Idehen 
President  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)


On 11/9/10 10:54 AM, Nathan wrote:

Kingsley Idehen wrote:

On 11/9/10 6:57 AM, Ian Davis wrote:

On Tue, Nov 9, 2010 at 11:23 AM, Nathannat...@webr3.org  wrote:

Pete Johnston wrote:

This document mentions the following class

It's all very simple really, when you remove all the conflated terms.


it's a description. 


Yes!

We are describing observations. Can't do this in thin air, must have a 
projection surface, hence the need for Documents.


You see, the whole Web of Data vs. Web of Documents is yet another false 
dichotomy. The Web is simply evolving its projection media from HTML 
documents (sorta like blank paper on to which you can scribble) to more 
Structured Documents (sorta like graph paper, what the spreadsheet kinda 
models). This new Document type is like graph paper, also like a 
spreadsheet (supports Name and Address reference values in cells), but 
with a 3-column restriction and unlimited rows.


HTTP lets us stream this powerful 3 column based graph paper document. 
The underlying conceptual schema (EAV) allows multiple representations 
(HTML+RDFa, RDF/XML, OData+Atom, OData+JSON, RDF-JSON, GData etc)  of 
the conceptual schema's model semantics.


We are using a graph paper like surface to hold the descriptions of our 
observations. We can use a myriad of syntaxes to achieve this goal as 
long as said syntaxes are based on a common conceptual schema.  Mapping 
an RDBMS to an RDF syntax isn't some new age magic, it's possible 
because there is a common conceptual schema at the base re. a DBMS based 
Relational Property Graphs vs its relative based on Relational Tables.


HTTP 200 OK means: Document Found.

Content-Type means: Document Content is in a given format.

Content-Location means: Document Location.

A URI is just an Identifier. We can Describe what isn't unambiguously 
Identified (Named); hence the use of Names since the beginning of 
shared cognition era re. human evolution.



--

Regards,

Kingsley Idehen 
President  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen

What would break, a question for implementors? (was Re: Is 303 really necessary?)


On 11/9/10 11:10 AM, Kingsley Idehen wrote:


A URI is just an Identifier. We can Describe what isn't 
unambiguously Identified (Named); hence the use of Names since the 
beginning of shared cognition era re. human evolution.


A URI is just an Identifier. We can't  Describe what isn't 
unambiguously Identified (Named); hence the use of Names since the 
beginning of shared cognition era re. human evolution.


--

Regards,

Kingsley Idehen 
President  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)


On Tue, 9 Nov 2010, Kingsley Idehen wrote:


On 11/9/10 11:10 AM, Kingsley Idehen wrote:






A URI is just an Identifier. We can't  Describe what isn't unambiguously 
Identified (Named);


Kingsley,

I think we can, though we might not be properly understood, e.g. Kingsley 
was great in Gandhi and Sexy Beast.


Wasn't this part of the summer's argument regarding literals as rdf:subjects , 
i.e.

Those opposed: But you might be misunderstood.
Those in favour: We'll take our chances.
?

Joel.







hence the use of Names since the beginning of shared 
cognition era re. human evolution.









--

Regards,

Kingsley Idehen President  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)


On 11/9/10 5:04 PM, joel sachs wrote:


A URI is just an Identifier. We can't  Describe what isn't 
unambiguously Identified (Named);


Kingsley,

I think we can, though we might not be properly understood, e.g. 
Kingsley was great in Gandhi and Sexy Beast.


Wasn't this part of the summer's argument regarding literals as 
rdf:subjects , i.e. 


Joel,

Let me be a little clearer re. my statement:

We can't produce high-fidelity descriptions of Things (Entities) if 
the description Subjects aren't unambiguously Identified.


I believe, via Linked Data,  we are seeking to produce high-fidelity 
Linked Data meshes that scale.


English is but one of several syntaxes.

Global scale is an integral goal of the mission, Methinks.

--

Regards,

Kingsley Idehen 
President  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)

2010-11-09 Thread Nathan


joel sachs wrote:

On 11/9/10 11:10 AM, Kingsley Idehen wrote:
A URI is just an Identifier. We can't  Describe what isn't 
unambiguously Identified (Named);


Kingsley,

I think we can, though we might not be properly understood, e.g. 
Kingsley was great in Gandhi and Sexy Beast.


Wasn't this part of the summer's argument regarding literals as 
rdf:subjects , i.e.


Those opposed: But you might be misunderstood.
Those in favour: We'll take our chances.
?


Perhaps you are both correct,

I believe what Kingsley is getting at, is that in order to refer to the 
description of something (thus something described), you need to have an 
unambiguous name (identifier for the purpose of referencing) to use as 
the subject in statements made about that thing, within the description 
( read as, a way of referring to a description of bar within a 
description named foo = bar, as described by foo = foo#bar ) - Not 
that foo#bar must be an unambiguous name for a thing in the IFP sense - 
rather an unambiguous way to say, on the web, the thing I am describing 
is the same thing bar, as described by foo.


And perhaps what you are saying, is the same thing Kingsley, as 
described by Ghandi and Sexy Beast, was great = 
ghandi-sexy-beast#kingsley


And, perhaps:

Those opposed: We'll take our chances.
Those in favour: But you might be misunderstood.

Best,

Nathan

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)


Kingsley,

I'm not sure that you're joking, so I'll answer:

It's unambiguous to those who know that Ben Kingsley was in Gandhi and 
Sexy Beast. It's probably close to unambiguous to those who know that Ben 
Kingsley is an actor, and Gandhi and Sexy Beast are movies. To everyone 
else, it's probably ambiguous, which is my point.


Joel.




On Tue, 9 Nov 2010, Kingsley Idehen wrote:


On 11/9/10 5:04 PM, joel sachs wrote:

On Tue, 9 Nov 2010, Kingsley Idehen wrote:


On 11/9/10 11:10 AM, Kingsley Idehen wrote:






A URI is just an Identifier. We can't  Describe what isn't unambiguously 
Identified (Named);


Kingsley,

I think we can, though we might not be properly understood, e.g. Kingsley 
was great in Gandhi and Sexy Beast.


To whom is this unambiguous?

Kingsley



Wasn't this part of the summer's argument regarding literals as 
rdf:subjects , i.e.


Those opposed: But you might be misunderstood.
Those in favour: We'll take our chances.
?




Joel.







hence the use of Names since the beginning of shared cognition era re. 
human evolution.









--

Regards,

Kingsley IdehenPresident  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen












--

Regards,

Kingsley Idehen President  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)



I guess what surprises me is your use of can't in We can't produce ... 
instead of shouldn't, as in We shouldn't produce high fidelity descriptions of 
things that aren't unambiguosly identified, because if we do, there will 
be no reliable way to merge descriptions from different sources.


I think  it's obvious that we can since we do it all the time. That we 
shouldn't may be true, although it is, I think you'll agree, a contested 
claim.


Joel.






On Tue, 9 Nov 2010, Kingsley Idehen wrote:


On 11/9/10 5:04 PM, joel sachs wrote:


A URI is just an Identifier. We can't  Describe what isn't unambiguously 
Identified (Named);


Kingsley,

I think we can, though we might not be properly understood, e.g. Kingsley 
was great in Gandhi and Sexy Beast.


Wasn't this part of the summer's argument regarding literals as 
rdf:subjects , i.e. 


Joel,

Let me be a little clearer re. my statement:

We can't produce high-fidelity descriptions of Things (Entities) if the 
description Subjects aren't unambiguously Identified.


I believe, via Linked Data,  we are seeking to produce high-fidelity Linked 
Data meshes that scale.


English is but one of several syntaxes.

Global scale is an integral goal of the mission, Methinks.

--

Regards,

Kingsley Idehen President  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)


On Tue, 9 Nov 2010, Nathan wrote:


joel sachs wrote:

On 11/9/10 11:10 AM, Kingsley Idehen wrote:
A URI is just an Identifier. We can't  Describe what isn't unambiguously 
Identified (Named);


Kingsley,

I think we can, though we might not be properly understood, e.g. Kingsley 
was great in Gandhi and Sexy Beast.


Wasn't this part of the summer's argument regarding literals as 
rdf:subjects , i.e.


Those opposed: But you might be misunderstood.
Those in favour: We'll take our chances.
?


Perhaps you are both correct,

I believe what Kingsley is getting at, is that in order to refer to the 
description of something (thus something described), you need to have an 
unambiguous name (identifier for the purpose of referencing) to use as the 
subject in statements made about that thing, within the description ( read 
as, a way of referring to a description of bar within a description named 
foo = bar, as described by foo = foo#bar ) - Not that foo#bar must be an 
unambiguous name for a thing in the IFP sense - rather an unambiguous way to 
say, on the web, the thing I am describing is the same thing bar, as 
described by foo.


And perhaps what you are saying, is the same thing Kingsley, as described by 
Ghandi and Sexy Beast, was great = ghandi-sexy-beast#kingsley


And, perhaps:

Those opposed: We'll take our chances.
Those in favour: But you might be misunderstood.

Best,

Nathan



Nathan,

Nathan, I definitely agree with your switcharoo -


Those opposed: We'll take our chances.
Those in favour: But you might be misunderstood.


Specifically, as it stands now, there is great scope for misunderstanding
when dealing with Linked Data. Perhaps the most egregious example is the
widely discredited owl:sameAs. The hope, I think, of Linked Data, is that,
as time goes by, the scope for misunderstanding will be greatly
diminished.

Regards -
Joel.

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)


On 11/9/10 5:59 PM, joel sachs wrote:

Kingsley,

I'm not sure that you're joking, so I'll answer:

It's unambiguous to those who know that Ben Kingsley was in Gandhi and 
Sexy Beast. It's probably close to unambiguous to those who know that 
Ben Kingsley is an actor, and Gandhi and Sexy Beast are movies. To 
everyone else, it's probably ambiguous, which is my point.


Yes, in the real-world.

On the Web it's totally ambiguous :-)

Kingsley


Joel.




On Tue, 9 Nov 2010, Kingsley Idehen wrote:


On 11/9/10 5:04 PM, joel sachs wrote:

On Tue, 9 Nov 2010, Kingsley Idehen wrote:


On 11/9/10 11:10 AM, Kingsley Idehen wrote:






A URI is just an Identifier. We can't  Describe what isn't 
unambiguously Identified (Named);


Kingsley,

I think we can, though we might not be properly understood, e.g. 
Kingsley was great in Gandhi and Sexy Beast.


To whom is this unambiguous?

Kingsley



Wasn't this part of the summer's argument regarding literals as 
rdf:subjects , i.e.


Those opposed: But you might be misunderstood.
Those in favour: We'll take our chances.
?




Joel.







hence the use of Names since the beginning of shared cognition 
era re. human evolution.









--

Regards,

Kingsley IdehenPresident  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen












--

Regards,

Kingsley IdehenPresident  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen











--

Regards,

Kingsley Idehen 
President  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)


On 11/9/10 6:01 PM, joel sachs wrote:


I guess what surprises me is your use of can't in We can't produce 
... instead of shouldn't, as in We shouldn't produce high fidelity 
descriptions of things that aren't unambiguosly identified, because if 
we do, there will be no reliable way to merge descriptions from 
different sources.


I think  it's obvious that we can since we do it all the time. That 
we shouldn't may be true, although it is, I think you'll agree, a 
contested claim.

Naturally, of course. Just my opinion.

Everything I say is inherently subjective :-)

Kingsley


Joel.






On Tue, 9 Nov 2010, Kingsley Idehen wrote:


On 11/9/10 5:04 PM, joel sachs wrote:


A URI is just an Identifier. We can't  Describe what isn't 
unambiguously Identified (Named);


Kingsley,

I think we can, though we might not be properly understood, e.g. 
Kingsley was great in Gandhi and Sexy Beast.


Wasn't this part of the summer's argument regarding literals as 
rdf:subjects , i.e. 


Joel,

Let me be a little clearer re. my statement:

We can't produce high-fidelity descriptions of Things (Entities) if 
the description Subjects aren't unambiguously Identified.


I believe, via Linked Data,  we are seeking to produce high-fidelity 
Linked Data meshes that scale.


English is but one of several syntaxes.

Global scale is an integral goal of the mission, Methinks.

--

Regards,

Kingsley IdehenPresident  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen












--

Regards,

Kingsley Idehen 
President  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)

2010-11-08 Thread Ian Davis

On Fri, Nov 5, 2010 at 9:53 AM, Leigh Dodds leigh.do...@talis.com wrote:
 So here's a couple of questions for those of you on the list who have
 implemented Linked Data tools, applications, services, etc:

 * Do you rely on or require HTTP 303 redirects in your application? Or
 does your app just follow the redirect?
 * Would your application tool/service/etc break or generic inaccurate
 data if Ian's pattern was used to publish Linked Data.


I used Denny Vrandečić's browser tool to test several Linked Data
browsers including Tabulator.

http://browse.semanticweb.org/?uri=http%3A%2F%2Fiandavis.com%2F2010%2F303%2Ftoucandays=7

Non of these showed any confusion between the toucan and its
description, nor did that throw warnings or errors about the lack of
303 or in fact make any reference to it (tabulator includes the
response as RDF but does not infer that the 200 response implies a
type of information resource, which I had assumed it would)


Cheers,

Ian

What would break, a question for implementors? (was Re: Is 303 really necessary?)

2010-11-05 Thread Leigh Dodds

Hi Michael,

On 5 November 2010 09:29, Michael Hausenblas
michael.hausenb...@deri.org wrote:
 It occurs to me that one of the main features of the Linked Data community
 is that we *do* things rather than having endless conversations what would
 be the best for the world out there. Heck, this is how the whole thing
 started. A couple of people defining a set of good practices and providing
 data following these practices and tools for it.

 Concluding. If you are serious about this, please go ahead. You have a very
 popular and powerful platform at your hand. Implement it there (and in your
 libraries, such as Moriarty), document it, and others may/will follow.

Yes, actually doing things does help more than talking. I sometimes
wonder whether as a community we're doing all the right things, but
that's another discussion ;)

Your suggestion about forging ahead is a good one, but it also reminds
me of Ian's original question: what would break if we used this
pattern?

So here's a couple of questions for those of you on the list who have
implemented Linked Data tools, applications, services, etc:

* Do you rely on or require HTTP 303 redirects in your application? Or
does your app just follow the redirect?
* Would your application tool/service/etc break or generic inaccurate
data if Ian's pattern was used to publish Linked Data.

Cheers,

L.

-- 
Leigh Dodds
Programme Manager, Talis Platform
Talis
leigh.do...@talis.com
http://www.talis.com

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)

2010-11-05 Thread Robert Fuller




So here's a couple of questions for those of you on the list who have
implemented Linked Data tools, applications, services, etc:

* Do you rely on or require HTTP 303 redirects in your application? Or
does your app just follow the redirect?


For sindice - no we do not rely on or require them, merely follow.


* Would your application tool/service/etc break or generic inaccurate
data if Ian's pattern was used to publish Linked Data.


It wouldn't break sindice.

However... with regard to publishing ontologies, we could expect 
additional overhead if same content is delivered on retrieving different 
Resources for example http://example.com/schema/latitude and 
http://example.com/schema/longitude . In such a case ETag could be used 
to suggest the contents are identical, but not sure that is a practical 
solution. I expect that without 303 it will be more difficult in 
particular to publish and process ontologies.


Rob.
--
Robert Fuller
Research Associate
Sindice Team
DERI, Galway
http://sindice.com/

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)


Robert Fuller wrote:
However... with regard to publishing ontologies, we could expect 
additional overhead if same content is delivered on retrieving different 
Resources for example http://example.com/schema/latitude and 
http://example.com/schema/longitude . In such a case ETag could be used 
to suggest the contents are identical, but not sure that is a practical 
solution. I expect that without 303 it will be more difficult in 
particular to publish and process ontologies.


Good point which needs discussed more, for instance FOAF returning 200 
OK's would be a real PITA and even worse than the 303 pattern, 3**s are 
definitely advisable in this case.


ps: introducing some form of ETag equality wouldn't be the best idea, it 
may be possible to use Content-Location and ETag together to cache and 
save doing the second request after a 303 though.


Best,

Nathan

RE: What would break, a question for implementors? (was Re: Is 303 really necessary?)

2010-11-05 Thread bill.roberts

Hi Nathan

I'm not saying you're wrong - but could you explain why it would be a pain for 
FOAF terms to return 200?  Which kinds of application are dereferencing those 
terms and relying on a 303 response?

eg  http://xmlns.com/foaf/0.1/Person currently 303s to 
http://xmlns.com/foaf/spec/

What would break if http://xmlns.com/foaf/0.1/Person returned that same content 
with a status code of 200?

Just trying to understand the issue

Bill


-Original Message-
From: public-lod-requ...@w3.org on behalf of Nathan
Sent: Fri 11/5/2010 12:45 PM
To: Robert Fuller
Cc: Leigh Dodds; Michael Hausenblas; Ian Davis; Linked Data community
Subject: Re: What would break, a question for implementors? (was Re: Is 303   
really necessary?)
 
Robert Fuller wrote:
 However... with regard to publishing ontologies, we could expect 
 additional overhead if same content is delivered on retrieving different 
 Resources for example http://example.com/schema/latitude and 
 http://example.com/schema/longitude . In such a case ETag could be used 
 to suggest the contents are identical, but not sure that is a practical 
 solution. I expect that without 303 it will be more difficult in 
 particular to publish and process ontologies.

Good point which needs discussed more, for instance FOAF returning 200 
OK's would be a real PITA and even worse than the 303 pattern, 3**s are 
definitely advisable in this case.

ps: introducing some form of ETag equality wouldn't be the best idea, it 
may be possible to use Content-Location and ETag together to cache and 
save doing the second request after a 303 though.

Best,

Nathan

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)


bill.robe...@planet.nl wrote:

Hi Nathan

I'm not saying you're wrong - but could you explain why it would be a pain for 
FOAF terms to return 200?  Which kinds of application are dereferencing those 
terms and relying on a 303 response?

eg  http://xmlns.com/foaf/0.1/Person currently 303s to 
http://xmlns.com/foaf/spec/

What would break if http://xmlns.com/foaf/0.1/Person returned that same content 
with a status code of 200?

Just trying to understand the issue


Hi Bill,

Good question :)

If you consider a basic linked data client, with a basic ontology/schema 
awareness, for instance one which shows peoples FOAF profiles and uses 
the nice rdfs:label's for properties rather than foaf:Person.


It's going to have to GET the ontology, now when it cycles through the 
properties it'll find http://xmlns.com/foaf/0.1/Person and GET it, then 
hopefully cache it against the URL specified in the [content?] location 
of the final request (be that 1 or many requests). When you 200 OK the 
response then the ontology will be stored against 
http://xmlns.com/foaf/0.1/Person so when you hit 
http://xmlns.com/foaf/0.1/knows you need to do another GET, and be 
returned a full ontology again, thus you end up with 40+ requests with 
full responses and 40+ cached versions of the single ontology. Unless 
you code around it in some way, make a provision for FOAF.


However, if you use 303's the then first GET redirects there, then you 
store the ontology against the redirected-to URI, you still have to do 
40+ GETs but each one is fast with no response-body (ontology sent down 
the wire) then the next request for the 303'd to URI comes right out of 
the cache. It's still 40+ requests unless you code around it in some 
way, but it's better than 40+ requests and 40+ copies of the single 
ontology.


The above, together with the deployment for FOAF is a v good reason 
*not* to use slash URIs for ontologies - ask Dan Bri about the FOAF 
rewrite rules for a second opinion on that :p


Hope that explains,

Best,

Nathan

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)

2010-11-05 Thread Leigh Dodds

Hi Robert,

Thanks for the response, good to hear from an implementor.

On 5 November 2010 10:41, Robert Fuller robert.ful...@deri.org wrote:
 ...
 However... with regard to publishing ontologies, we could expect
 additional overhead if same content is delivered on retrieving different
 Resources for example http://example.com/schema/latitude and
 http://example.com/schema/longitude . In such a case ETag could be used
 to suggest the contents are identical, but not sure that is a practical
 solution. I expect that without 303 it will be more difficult in
 particular to publish and process ontologies.

This is useful to know thanks. I don't think the ETag approach works
as it's intended to version a specific resource, not be carried across
resources.

One way to avoid the overhead is to strongly recommend # URIs for
vocabularies. This seems to be increasingly the norm. It also makes
them easier to work with (you often want the whole document)

L.

-- 
Leigh Dodds
Programme Manager, Talis Platform
Talis
leigh.do...@talis.com
http://www.talis.com

RE: What would break, a question for implementors? (was Re: Is 303 really necessary?)

2010-11-05 Thread bill.roberts

Hi Nathan - thanks for clear answer. I see the point and also the argument for 
using hash URIs with ontologies.

In practice how I get round this prob is to preload my triple store with the 
handful of common ontologies I know I'm going to use, so don't need to deref 
them as I go along.

Cheers

Bill


-Original Message-
From: Nathan [mailto:nat...@webr3.org]
Sent: Fri 11/5/2010 1:12 PM
To: bill.robe...@planet.nl
Cc: public-lod@w3.org; Dan Brickley
Subject: Re: What would break, a question for implementors? (was Re: Is 303   
really necessary?)
 
bill.robe...@planet.nl wrote:
 Hi Nathan
 
 I'm not saying you're wrong - but could you explain why it would be a pain 
 for FOAF terms to return 200?  Which kinds of application are dereferencing 
 those terms and relying on a 303 response?
 
 eg  http://xmlns.com/foaf/0.1/Person currently 303s to 
 http://xmlns.com/foaf/spec/
 
 What would break if http://xmlns.com/foaf/0.1/Person returned that same 
 content with a status code of 200?
 
 Just trying to understand the issue

Hi Bill,

Good question :)

If you consider a basic linked data client, with a basic ontology/schema 
awareness, for instance one which shows peoples FOAF profiles and uses 
the nice rdfs:label's for properties rather than foaf:Person.

It's going to have to GET the ontology, now when it cycles through the 
properties it'll find http://xmlns.com/foaf/0.1/Person and GET it, then 
hopefully cache it against the URL specified in the [content?] location 
of the final request (be that 1 or many requests). When you 200 OK the 
response then the ontology will be stored against 
http://xmlns.com/foaf/0.1/Person so when you hit 
http://xmlns.com/foaf/0.1/knows you need to do another GET, and be 
returned a full ontology again, thus you end up with 40+ requests with 
full responses and 40+ cached versions of the single ontology. Unless 
you code around it in some way, make a provision for FOAF.

However, if you use 303's the then first GET redirects there, then you 
store the ontology against the redirected-to URI, you still have to do 
40+ GETs but each one is fast with no response-body (ontology sent down 
the wire) then the next request for the 303'd to URI comes right out of 
the cache. It's still 40+ requests unless you code around it in some 
way, but it's better than 40+ requests and 40+ copies of the single 
ontology.

The above, together with the deployment for FOAF is a v good reason 
*not* to use slash URIs for ontologies - ask Dan Bri about the FOAF 
rewrite rules for a second opinion on that :p

Hope that explains,

Best,

Nathan

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)


bill.robe...@planet.nl wrote:

Hi Nathan - thanks for clear answer. I see the point and also the argument for 
using hash URIs with ontologies.


Most welcome, and glad it helped :)


In practice how I get round this prob is to preload my triple store with the 
handful of common ontologies I know I'm going to use, so don't need to deref 
them as I go along.


Snap, however the big caveat is that as soon as I followed the paradigm 
a bit further and hit client side applications which use the web as a 
data tier (read write web of linked data) where typically you just 
leverage HTTP caching, and where a triple store isn't particularly ideal 
(or even needed) the importance of these things became somewhat more 
noticeable.


I have to say, that if I hadn't taken this move, then I probably 
wouldn't be quite as passionate as I am about these things. Linked Data 
should (must?) be HTTP friendly, and slash URIs for both ontologies and 
data are most definitely not, even to deal with foaf with the current 
303's you need to hard code rules around it, or embed the ontology in 
your application (in js code!).


Give it some time and I'm sure it won't just be a handful of us shouting 
OMG that was a mistake and a half.


Best,

Nathan

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)

2010-11-05 Thread Ian Davis

On Fri, Nov 5, 2010 at 12:12 PM, Nathan nat...@webr3.org wrote:
 However, if you use 303's the then first GET redirects there, then you store
 the ontology against the redirected-to URI, you still have to do 40+ GETs
 but each one is fast with no response-body (ontology sent down the wire)
 then the next request for the 303'd to URI comes right out of the cache.
 It's still 40+ requests unless you code around it in some way, but it's
 better than 40+ requests and 40+ copies of the single ontology.

But in practice, don't you look in your cache first? If you already
have a label for foaf:knows because you looked up foaf:mbox a few
seconds ago why would you issue another request?

Ian

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)

2010-11-05 Thread Robert Fuller




On 05/11/10 15:06, Ian Davis wrote:

On Fri, Nov 5, 2010 at 12:12 PM, Nathannat...@webr3.org  wrote:

However, if you use 303's the then first GET redirects there, then you store
the ontology against the redirected-to URI, you still have to do 40+ GETs
but each one is fast with no response-body (ontology sent down the wire)
then the next request for the 303'd to URI comes right out of the cache.
It's still 40+ requests unless you code around it in some way, but it's
better than 40+ requests and 40+ copies of the single ontology.


But in practice, don't you look in your cache first? If you already
have a label for foaf:knows because you looked up foaf:mbox a few
seconds ago why would you issue another request?


Sindice would, because Fred could also define a label for foaf:knows in 
the flintstone schema. The Sindice contextualised reasoning is performed 
in a sandbox to ensure that Fred's malicious schema isn't going to 
pollute any inferencing from your document, unless your document also 
references Fred's schema. Without checking we can't be sure that 
foaf:knows and foaf:mbox are defined in the same ontology.



--
Robert Fuller
Research Associate
Sindice Team
DERI, Galway
http://sindice.com/

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)

2010-11-05 Thread Kingsley Idehen


On 11/5/10 9:13 AM, bill.robe...@planet.nl wrote:


Hi Nathan - thanks for clear answer. I see the point and also the 
argument for using hash URIs with ontologies.


In practice how I get round this prob is to preload my triple store 
with the handful of common ontologies I know I'm going to use, so 
don't need to deref them as I go along.


Cheers

Bill



Bill,

What happens when the ontologies evolve?


Kingsley




-Original Message-
From: Nathan [mailto:nat...@webr3.org]
Sent: Fri 11/5/2010 1:12 PM
To: bill.robe...@planet.nl
Cc: public-lod@w3.org; Dan Brickley
Subject: Re: What would break, a question for implementors? (was Re: 
Is 303   really necessary?)


bill.robe...@planet.nl wrote:
 Hi Nathan

 I'm not saying you're wrong - but could you explain why it would be 
a pain for FOAF terms to return 200?  Which kinds of application are 
dereferencing those terms and relying on a 303 response?


 eg http://xmlns.com/foaf/0.1/Person currently 303s to 
http://xmlns.com/foaf/spec/


 What would break if http://xmlns.com/foaf/0.1/Person returned that 
same content with a status code of 200?


 Just trying to understand the issue

Hi Bill,

Good question :)

If you consider a basic linked data client, with a basic ontology/schema
awareness, for instance one which shows peoples FOAF profiles and uses
the nice rdfs:label's for properties rather than foaf:Person.

It's going to have to GET the ontology, now when it cycles through the
properties it'll find http://xmlns.com/foaf/0.1/Person and GET it, then
hopefully cache it against the URL specified in the [content?] location
of the final request (be that 1 or many requests). When you 200 OK the
response then the ontology will be stored against
http://xmlns.com/foaf/0.1/Person so when you hit
http://xmlns.com/foaf/0.1/knows you need to do another GET, and be
returned a full ontology again, thus you end up with 40+ requests with
full responses and 40+ cached versions of the single ontology. Unless
you code around it in some way, make a provision for FOAF.

However, if you use 303's the then first GET redirects there, then you
store the ontology against the redirected-to URI, you still have to do
40+ GETs but each one is fast with no response-body (ontology sent down
the wire) then the next request for the 303'd to URI comes right out of
the cache. It's still 40+ requests unless you code around it in some
way, but it's better than 40+ requests and 40+ copies of the single
ontology.

The above, together with the deployment for FOAF is a v good reason
*not* to use slash URIs for ontologies - ask Dan Bri about the FOAF
rewrite rules for a second opinion on that :p

Hope that explains,

Best,

Nathan




--

Regards,

Kingsley Idehen 
President  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen

Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)