Re: [Ltru] Language tag education and negotiation

I sent in a mail, and the responses I got back was that 1 is always the
default, and that as far as the spec is concerned, the only reliable
information is the relative magnitude of the values. Neither the client nor
server can depend on anything else in the absence of negotiation. That is,
for all the server can depend on,

"en, fr;q=0.99999, de;q=0.99998"
    is the same as
"en, fr;q=0.00002, de;q=0.00001".

Mark

On Wed, May 7, 2008 at 12:31 AM, Martin Duerst <duerst@it.aoyama.ac.jp>
wrote:

> At 05:29 08/05/05, Mark Davis wrote:
> >Unfortunately, the specs are ill-defined regarding the q values.
>
> Yes indeed. I have reported this to the HTTP WG.
>
>
> >Take the following example:
> >
> >a, b;q=0.7, c, d;q=0.5, e, f;q=0.9, g
> >
> >The specs do not distinguish between at least two different possible
> reasonable interpretations of what the q values of c, e, and g are:
> >    * c;q=1.0, e;q=1.0, g;q=1 // always 1
> >    * c;q=0.7, e;q=0.5, g;q=0.9 // always same as previous
> >Our guess is that the user meant #2, but it is only a guess.
>
> My guess would be to use 1.0 as a default, because this is
> consistent with other headers, and allows concatenation and
> splitting of headers without going through hoops. Please
> remember that the above is protocol syntax, not what the
> user should see or would edit.
>
> >And even once that ambiguity is cleared up, nobody knows what the meaning
> of the numbers really is. My native tongue is English, I can understand
> Swiss German and German, my French is rusty, and Italian basic. Which of
> these should I use?
> >    * en, gsw, de, fr, it
> >    * en, gsw;q=0.9, de;q=0.9, fr;q=0.8, it;q=0.7
> >    * en, gsw;q=0.5, de;q=0.4, fr;q=0.3, it;q=0.2
> >    * en, gsw;q=0.99, de;q=0.95, fr;q=0.03, it;q=0.02
> >All are descending order, but depending on what algorithm the consumer of
> the tags uses, they could have very different results. Without being able to
> have any consistent expectations for what the q numbers mean, producers of
> tags don't know what settings to provide or what difference it will make,
> and consumers of tags don't know what the producers meant.
>
> There is a certain aspect of tuning, which indeed currently doesn't work
> because there isn't enough actual use on the server side. But basically,
> the idea is simple: the values get multiplied with the corresponding
> quality values for the documents on the server side.
>
> So the way you should think is that you set gsw to 0.5 if you would
> be satisfied to get the English document if the server thinks that the
> English document it has is more than half as good than the corresponding
> gsw document, but you would prefer to get the gsw document if the server
> thinks that the corresponding English document is less than half as
> good in quality than the corresponding gsw document.
>
> Of course, "half as good in quality" is then the difficult piece of
> information, but ideas for measuring this might be the time it takes
> to read for a native reader, the amount of "updateness" (i.e. 70%
> of the document are up-to-date -> document quality 0.7), or similar
> measures. You can go into very fine details (and they way I know you,
> you probably will), but while my considerations above won't help
> you figure out the *exact* values for your q-values, they should
> be enough to help you decide among the above listed four variants.
>
> My personal guess is that
>    en, gsw;q=0.5, de;q=0.4, fr;q=0.3, it;q=0.2
> maybe most reasonable, but it's up to you to decide.
>
> Regards,   Martin.
>
>
>
> #-#-#  Martin J. Du"rst, Assoc. Professor, Aoyama Gakuin University
> #-#-#  http://www.sw.it.aoyama.ac.jp       mailto:duerst@it.aoyama.ac.jp
>
>


-- 
Mark