W3C home > Mailing lists > Public > semantic-web@w3.org > December 2012

Re: Well Behaved RDF - Taming Blank Nodes, etc.

From: Hugh Glaser <hg@ecs.soton.ac.uk>
Date: Fri, 14 Dec 2012 11:16:57 +0000
To: Lee Feigenbaum <lee@thefigtrees.net>
CC: Pat Hayes <phayes@ihmc.us>, David Booth <david@dbooth.org>, "semantic-web Web" <semantic-web@w3.org>
Message-ID: <387E72E216DF1247A2F8ED4819C93BA71E38FAFA@UOS-MSG00041-SI.soton.ac.uk>
Hi Lee,
Great set of questions (my reformatting to make response easier).
I too would love to see peoples' answers.
I don't think I have seen a response - any takers?

On 13 Dec 2012, at 14:41, Lee Feigenbaum <lee@thefigtrees.net> wrote:

> On 12/13/2012 2:00 AM, Pat Hayes wrote:
>> And that is exactly what blank nodes are for, so I would like to use them to do that.
> What is the value of using a blank node here rather than minting an arbitrary URI?
> Is there inherent value in using something because that's what it was designed for?

> Is there a property of blank nodes that you need that URIs don't have here?

> Is it the cost of minting an arbitrary URI?

> Is it the potential cost of having two URIs for the thing sometime down the road?

> Something else?

>> Another example: a picture of some celebrity standing next to a horse. I have a URI for the celebrity, but I don't have and don't need one for the horse: and if I were to invent one for each horse, then I could no longer query for retrieval of a picture of that person with "a horse", but would have to remember the URi for each of the bloody horses. But nobody gives a damn about the particular horse.
> Could you explain this more? Because I'm picturing just doing:
> SELECT ?photo {
>   ?photo a :Photograph ;
>        :depicts :ThePerson ;
>        :depicts [ a :Horse ] ;
>   .
> }
> ...which works fine whether the horse is represented with a blank node or a URI.
> Lee
Received on Friday, 14 December 2012 11:18:01 UTC

This archive was generated by hypermail 2.4.0 : Tuesday, 5 July 2022 08:45:31 UTC