- From: Sean B. Palmer <sean@mysterylights.com>
- Date: Sat, 2 Mar 2002 23:34:59 -0000
- To: <w3c-wai-er-ig@w3.org>
In EARL, the TestSubject is the thing being evaluated. There are two requirements for identifying test subjects in EARL: a) we must be able to refer to anything, and b) we must be very clear about what is being identified. Examples of things that we may want to evaluate in EARL are:- * A web page http://example.org/ on a particular date * A part of a web page - just an element, or a few elements * An accessibility tool, or a User Agent This much we already know. In EARL 0.95, sometimes we have a necessary level of indirection. For example, if you want to point to the page http://example.org/ as it was on 2002-03-02, you can't just do something like:- <http://example.org/> earl:fails :SomeTest; earl:date "2002-03-02" . because you'll lose the date information on merging. So instead, we create a new thing - bNoded, or with a URI - something like [ earl:testSubject <http://example.org/>; earl:date "2002-03-02" ] . This can be read as "a thing which is the web content at http://example.org/ on the date 2002-03-02". In fact, there is some information left out there. We don't really know that we're evaluating a bit of WebContent at all... [ a earl:WebContent; earl:date "2002-03-02"; earl:testSubject <http://example.org/tool> ] . [ a earl:Tool; earl:date "2002-03-02"; earl:testSubject <http://example.org/tool> ] . In this case, it's clear(er) what's being evaluated. In the top example, we're evaluating the documentation for the tool, and in the bottom example we're evaluating the tool documented at http://example.org/tool. Unfortunately, there's no way that we can either a) force people to use a type arc, or b) deduce what the author of the URI *means* by it, unless they have stated that at the resource itself. So there's a problem there - ambiguity. I previously resolved [1] to clear this up by introducing two new properties that would take the place of testSubject: earl:reprOf, and earl:documentation. For example (now assuming an EARL 1.0 namespace):- [ earl:reprOf <http://example.org>; earl:date "2002-03-02" ] . [ earl:documentation <http://example.org>; earl:date "2002-03-02" ] . rdf:type arcs aren't strictly necessary here since we know that the domain of earl:reprOf is earl:WebContent, and that the domain of earl:documentation is a union of earl:Tool and earl:UserAgent. But it isn't necessary that we deprecate testSubject if people want to include it; we can rely on people using rdf:type to tell us the kind of content (as we do in EARL 0.95). A schema snippet for this is at [2]. So there's a choice for EARL 1.0:- a) Use testSubject and not reprOf/documentation. b) Let people choose: testSubject or reprOf/documentation c) Use reprOf/documentation and not testSubject Option a will depend upon people including an rdf:type arc, option b may do if they choose to use testSubject, and the latter option will not rely on rdf:type at all since the domains will take care of it. There are also some issues about identifying bits of representations etc., but that's not strictly a part of this debate, IMO. Cheers, [1] http://lists.w3.org/Archives/Public/w3c-wai-er-ig/2001Dec/0018 [2] earl:TestSubject rdfs:subClassOf [ daml:onProperty earl:testSubject; daml:cardinality "1" ] . earl:reprOf rdfs:subPropertyOf earl:testSubject . earl:documentation rdfs:subProperty earl:testSubject . -- Kindest Regards, Sean B. Palmer @prefix : <http://purl.org/net/swn#> . :Sean :homepage <http://purl.org/net/sbp/> .
Received on Saturday, 2 March 2002 18:34:43 UTC