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Re: The king is dressed in void

From: Martin Hepp <martin.hepp@uibk.ac.at>
Date: Thu, 19 Jun 2008 15:08:43 +0200
Message-ID: <485A5A5B.9060400@uibk.ac.at>
To: Yves Raimond <yves.raimond@gmail.com>
CC: Giovanni Tummarello <giovanni.tummarello@deri.org>, "Hausenblas, Michael" <michael.hausenblas@joanneum.at>, public-lod@w3.org, Semantic Web <semantic-web@w3.org>
>However, there are some cases where you can't really afford that, for
>example when "looking inside" takes too much time - for example
>because of the size of "inside".

But how do you decide which part of the "inside" is contained in the "outside" description? If you want all details from the inside in the outside, then you have to replicate the whole inside - which does not gain anything. And if the outside is just a subset (or even: proper abstraction) of the inside, then you will face "false positive" (the outside indicates something would be inside, but it actually isn't) and "false negative" (there is something inside which the outside does not tell) situations. Now for me the whole discussion boils down to the question on whether one can produce good descriptions that are (1) substantially shorter than the inside data and (2), on average, keep the false positive and false negative cases low. So you would have to find a proper trade-off and then show by means of a quantitative evaluation that there are relevant situations in which your approach increases retrieval performance.

Btw, the problem seems to me pretty much analog to full text vs. keyword-based information retrieval. And I guess there the trend goes to clever indexing of the full inside data than relying on the manually created outside description. From my experience, explicit keywords are now less and less relevant.


Best
Martin
http://www.heppnetz.de



Yves Raimond wrote:
> Hello Giovanni!
>
>   
>> These are my final observations on this matter (then i am out :-)
>> promised).. but as i said if i ever encounter myself the need for such
>> a thing i'll share the use cases and similarly if such a thing comes
>> to life and can add interesting features, we're pretty quick to
>> implement support for it.
>>     
>
> Just a small point, as I feel there's a disagreement on what we're
> actually trying to achieve here :-)
> I think you come from the "go and look at this rdf file or this
> end-point to see what's inside" point-of-vue (which is perfectly fine
> from a sindice perspective :) )
> However, there are some cases where you can't really afford that, for
> example when "looking inside" takes too much time - for example
> because of the size of "inside".
>
> Cheers!
> y
>
>
>   

-- 

-----------------------------------
martin hepp, http://www.heppnetz.de
mhepp@computer.org, skype mfhepp
Received on Thursday, 19 June 2008 20:55:28 UTC

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