- From: Sean B. Palmer <sean@mysterylights.com>
- Date: Sun, 9 Dec 2001 17:17:30 -0000
- To: <w3c-wai-er-ig@w3.org>
> > 03:15:33 <sbp> * Remove testSubject > > 03:15:40 <sbp> * Add reprOf > > I'm concerned this moves away from EARL as being > general purpose evaluate/report on anything language, Allow me to alleviate your anxiety. Firstly, the property is not being changed, it is being renamed. "testSubject" didn't really have a fixed meaning based upon Web architecture terms as set out in RFC 2396 and 2616, and so the "what is identified?" problem started to creep is. Secondly, the threading that you're worried is being *introduced* to EARL has been there since Aaron suggested to use a resource and a timestamp. A resource is a thread; it has a number of entities corresponsing to it over time. We expect pages to change, as they get corrected, as new items come in, or whatever, but we expect the mapping from the URI to the resource (the denotation, the semantics of the identifier) to be consistent, otherwise the Web would not be very useful. Thirdly, this does not stop people from evaluating anything; I agree that that is a very big strength of EARL, and will always be careful to preserve it. This change simply represents a clearer definition of semantics when evaluating WebContent. You can still evaluate tool and user agents, although I am thinking about how to do it. Let me run through the various methods. EARL Evaluation: x asserts { y passes z } . Let us just concentrate on the structure of "y", the TestSubject. The TestSubject is not some stand-in for what is being evaluated, it *is* the thing being evaluated. There are plenty of discussions about what constitutes a resource in HTTP space... TimBL says that HTTP resources are necessarily generic documents. Roy Fielding believes that they can be anything. Al Gilman often points out that HTTP resources can be better modelled as service pools. Because we want to be as consistent as we possibly can with these views, we'll follow the "be liberal in what you accept, and conservative in what you do" axiom, and accept anything. That simply means, we do not ask people to use URI references for the TestSubject when it's of type WebContent... but I digress. The W3C homepage http://www.w3.org/ is the concept of the W3C homepage... it is always the home of the W3C. Usually, I will want to say that a particular representation of it passes a certain checkpoint. The test subject in that case will be:- :W3CPage earl:reprOf <http://www.w3.org/>; earl:date "2001-12-09"; dc:format "text/html" . This is the standard use for EARL; standard in that it will be most common. Note that because the domain of "earl:reprOf" is "earl:WebContent", we do not really need to state that explicitly (although it may help if we do). Now, we may also want to rate the homepage as a great piece of work. In that case, we are not talking about any one particular serialization, but the concept of the homepage itself. Well, that already has a URI... the test subject is simply:- <http://www.w3.org/> a earl:TestSubject . I don't think that this will be a very common use of EARL, but it's there in case anyone needs it. We don't want to restrict people at all in what they can evaluate. The next use for EARL will be to evaluate things which aren't necessarily generic documents, but are tools, and so forth. Let's take a UserAgent called "MyUA", based as MyUA.org (with apologies to anyone who comes up with MyUA). We can use any identifier for the tool, in absence of knowing whether the homepage for the tool identifies the tool or the homepage. I think that usually it will be the homepage, because otherwise the tool would have no homepage... this is a murky area, but we can create a property that bulldozes over the argument by saying "if you suport x POV, then y, if you support q POV, then p". :MyUA a earl:UserAgent; earl:homepage <http://myua.org/> . Where "homepage" is a special property (that may need renaming) to say that the subject either identifies the tool described by, or the tool at, as appropriate. Either way, doesn't matter now; EARL is firmly in control :-) So this simply clarifies what is meant by the important identification properties in EARL, so that people can be much clearer about what they identify. I hope that it is consistent with the views of as many people as I could possibly make it, and most notably the URI and HTTP RFCs. Cheers, -- Kindest Regards, Sean B. Palmer @prefix : <http://purl.org/net/swn#> . :Sean :homepage <http://purl.org/net/sbp/> .
Received on Sunday, 9 December 2001 12:18:32 UTC