Re: [UCR] The Use Case previously known as publication

Axel Polleres wrote:
> Hirtle, David wrote:
>> Hi Chris,
>>
>>
>>> The word "intensional" is being used in a way that I am unfamiliar 
>>> with.  The text seems to imply that intensional == implicit (which 
>>> is isn't), and is contrasted with "factual" which is equated with 
>>> "extensional" (which it also isn't).  
>>
>>
>> The use case is heavily based on Axel's
>> http://www.w3.org/2005/rules/wg/wiki/UCR/Candidate_Use_Cases_for_2nd_Dra
>> ft/PublicationAlternative
>>
>> and the intensional vs. extensional distinction came from there. Axel
>> explained it in an earlier email as:
>>
>>   This goes along with the notion in deductive databases to distinguish
>>   between extensional (facts) and intensional (rules) knowledge.
>
> This terminology is common in DB textbooks and surveys, where stored 
> factual knowledge is called intensional database (EDB) whereas views, 
> i.e. implicitly defined knowledge is called the "intensional database" 
> (EDB). Since the example was meant to demonstrate exactly this, that 
> rules can provide for defining metadata as such non-materialized views,
> I still find the term appropriate, see e.g.
> H. Gallaire, J. Minker, and J. M. Nicolas. Logic and databases : a 
> deductive approach. ACM Surveys, 16(2), 1984.

It's not uncommon for computer scientists to butcher terms from 
philosophy whose meaning they don't fully understand.  Like ontology and 
property, for example.  I'll now add this one to the list.  I can 
certainly see where the similarity between intensional and 
nonmaterialized views may have come from, but nonmaterialized views are 
not intensional.  I don't want to be party to yet another semantic web 
misuse of terms. 

>>> The text also seems to imply that e.g. "Every science fiction movie 
>>> is a movie" is implicit and intensional - but the mere fact of 
>>> saying it makes it explicit, so I'm really not sure what you mean.
>
> I mean that this rule makes whenever you give a fact:
>
> X is a sciFiMovie.
>
> then you implicitly also define the fact
>
> X is a movie.
>
> without the need to make this explicit.
> Clearly this very simple form of implicit knowledge can already 
> defined using, e.g.
> RDFS, but not the more involved rules such as

David pointed this out at the telecon, and I see the point.  In a sense 
you are capturing implicit knowledge with rules.  So that usage is 
probably OK, as long as intensional is removed.

> "All movies listed at http://alternativemdb.example.org/  are 
> independent movies" and extensions thereof,
> where the source (context) where the metadata comes from plays a role, 
> etc.
>
>> Well, "Every science fiction movie is a movie" *is* implicit, until
>> being made explicit by rules...
>>
>>> Unless I'm missing something, this does not correspond to any 
>>> meaning I know, or can find, of intensional (or extensional, for 
>>> that matter).  I don't think "intensional" or "implicit" is what you 
>>> want here, so I suggest not confusing a reader with obscure 
>>> terminology that is used incorrectly. 
>>
>> Whether used correctly or not, I agree that it's probably not necessary
>> to the use case. 
>
>  Now as you say it, the only argument that could count against IDB/EDB 
> distinction might be that it is slightly misinterpretable, since in 
> the deductive database use, EDB/IDB are often viewed disjoint IIRC, 
> which is too restrictive in general...

No, the argument is that this is not what intensional means in the 
dictionary, which is what the vast majority of our audience will use to 
look it up.  I am religious about this and I want the term removed.

>>> To be constructive, how about something like, "Publishing rules for 
>>> interlinked metadata"
>>
>> I'd be fine with this, but let's see what Axel has to say.
>
> I am not religous about these terms, although I thought they properly 
> describe what I wanted to say.

To a database audience, perhaps, but not the rest of the world.

Anyway, since this sounds like complaisance, I have done a pretty simple 
edit pass on the wiki page 
[http://www.w3.org/2005/rules/wg/wiki/UCR/Publication_of_Intensional%2C_Interlinked_Metadata].  
I removed intensional completely, and reworded a couple places around 
"implicit" to make the intenTion more explicit. 

I think the key points from this use case are:

enhancing published metadata standards by capturing implicit knowledge 
with rules, and scope

and these still come through.

-Chris

>
> best regards,
> axel
>
>
>>> -----Original Message-----
>>> From: public-rif-wg-request@w3.org 
>>> [mailto:public-rif-wg-request@w3.org] On Behalf Of Chris Welty
>>> Sent: Monday, June 26, 2006 11:05 PM
>>> To: Public-Rif-Wg (E-mail)
>>> Subject: [UCR] The Use Case previously known as publication
>>>
>>>
>>>
>>> Specific comments on the new text for Use Case 2.10:
>>>
>>> The word "intensional" is being used in a way that I am unfamiliar 
>>> with.  The text seems to imply that intensional == implicit (which 
>>> is isn't), and is contrasted with "factual" which is equated with 
>>> "extensional" (which it also isn't).  The text also seems to imply 
>>> that e.g. "Every science fiction movie is a movie" is implicit and 
>>> intensional - but the mere fact of saying it makes it explicit, so 
>>> I'm really not sure what you mean.
>>>
>>> Unless I'm missing something, this does not correspond to any 
>>> meaning I know, or can find, of intensional (or extensional, for 
>>> that matter).  I don't think "intensional" or "implicit" is what you 
>>> want here, so I suggest not confusing a reader with obscure 
>>> terminology that is used incorrectly.
>>> I realize "intensional" is a fairly slippery concept, and I don't 
>>> want to get the WG bogged down in defining it.
>>>
>>> To be constructive, how about something like, "Publishing rules for 
>>> interlinked metadata"
>>>
>>> -Chris
>>>
>>> -- 
>>> Dr. Christopher A. Welty                    IBM Watson Research Center
>>> +1.914.784.7055                             19 Skyline Dr.
>>> cawelty@frontiernet.net                     Hawthorne, NY 10532
>>> http://www.research.ibm.com/people/w/welty
>>>
>>>
>>>
>>>
>>
>>
>>
>
>


-- 
Dr. Christopher A. Welty                    IBM Watson Research Center
+1.914.784.7055                             19 Skyline Dr.
cawelty@frontiernet.net                     Hawthorne, NY 10532
http://www.research.ibm.com/people/w/welty

Received on Wednesday, 28 June 2006 13:20:32 UTC